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defect phone glass
[ { "abstract": "Defect detection based on machine vision and machine learning techniques has drawn much attention in recent years. Deep learning is very suitable for such segmentation and detection tasks and has become a promising research area. Surface quality inspection is essentially important in the manufacturing of mobile phone back glass (MPBG) Different types of defects are produced because of the imperfection of the manufacturing technique. Unlike general transparent glass, screen printing glass has totally different reflection and scattering characteristics, which means the traditional dark field imaging system is not suitable for this task. Meanwhile, the imaging system requires high resolution since the minimum defect size can be 0.005 mm2. According to the imaging characteristics of screen printing glass, this paper proposes a coaxial bright field (CBF) imaging system and low angle bright field (LABF) imaging system, and 8K line scan complementary metal oxide semiconductor(CMOS) cameras are utilized to capture images with the resolution size of 16,000*8092. The CBF system is applied for the weak scratch and discoloration defects while the LABF system is applied for the dent defect. A symmetric convolutional neural network composed of encoder and decoder structures is proposed based on U net, which produces a semantic segmentation with the same size as the original input image. More than 10,000 original images were captured, and more than 30,000 defective and non defective images were manually annotated in the glass surface defect dataset (GSDD) Verified by the experiments, the results showed that the average precision reaches more than 91% and the average recall rate reaches more than 95% The method is very suitable for the surface defect inspection of screen printing mobile phone back glass.", "author_names": [ "Jia-Bin Jiang", "Pin Cao", "Zichen Lu", "Weimin Lou", "Yongying Yang" ], "corpus_id": 219776934, "doc_id": "219776934", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Surface Defect Detection for Mobile Phone Back Glass Based on Symmetric Convolutional Neural Network Deep Learning", "venue": "", "year": 2020 }, { "abstract": "In this paper, we propose an unsupervised background reconstruction method to detect defects on surfaces with unevenly distributed textures. An improved deep convolutional autoencoder is utilized to reconstruct the textured background of the original image as a defect free reference. Specifically, a weighted loss function based on structural similarity (SSIM) is utilized to adapt to the unevenly distributed texture background and improve the reconstruction accuracy. Furthermore, combined with the reconstructed defect free reference, a novel difference analysis method based on the discrete cosine transform (DCT) is given to accurately segment the defect regions from the original image. A series of experiments for the defect detection on mobile phone cover glass (MPCG) are conducted. The processing time for an image of 512 x 512 pixels is only 20 ms, which satisfies the requirement of online detection. The experimental results verify the effectiveness of the proposed method.", "author_names": [ "Chengkan Lv", "Zheng-Tao Zhang", "Fei Shen", "Feifei Zhang", "Hu Su" ], "corpus_id": 210232808, "doc_id": "210232808", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "A Fast Surface Defect Detection Method Based on Background Reconstruction", "venue": "International Journal of Precision Engineering and Manufacturing", "year": 2019 }, { "abstract": "Recently, researchers have been studying methods to introduce deep learning into automated optical inspection (AOI) systems to reduce labor costs. However, the integration of deep learning in the industry may encounter major challenges such as sample imbalance (defective products that only account for a small proportion) Therefore, in this study, an anomaly detection neural network, dual auto encoder generative adversarial network (DAGAN) was developed to solve the problem of sample imbalance. With skip connection and dual auto encoder architecture, the proposed method exhibited excellent image reconstruction ability and training stability. Three datasets, namely public industrial detection training set, MVTec AD, with mobile phone screen glass and wood defect detection datasets, were used to verify the inspection ability of DAGAN. In addition, training with a limited amount of data was proposed to verify its detection ability. The results demonstrated that the areas under the curve (AUCs) of DAGAN were better than previous generative adversarial network based anomaly detection models in 13 out of 17 categories in these datasets, especially in categories with high variability or noise. The maximum AUC improvement was 0.250 (toothbrush) Moreover, the proposed method exhibited better detection ability than the U Net auto encoder, which indicates the function of discriminator in this application. Furthermore, the proposed method had a high level of AUCs when using only a small amount of training data. DAGAN can significantly reduce the time and cost of collecting and labeling data when it is applied to industrial detection.", "author_names": [ "Tang Tang", "Wei-Han Kuo", "Jauh-Hsiang Lan", "Chien-Fang Ding", "Hakiem Hsu", "Hong-Tsu Young" ], "corpus_id": 219726774, "doc_id": "219726774", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "Anomaly Detection Neural Network with Dual Auto Encoders GAN and Its Industrial Inspection Applications", "venue": "Sensors", "year": 2020 }, { "abstract": "Abstract Ultra thin curved (2.5D, 3D) glass is widely used in the most recently developed smartphones, and the market demand for it is steadily increasing. The high precision ultra thin glass molding process (UTGMP) is very important in the fabrication of high quality 2.5D/3D ultra thin glass for smartphones; however, the UTGMP, with its high energy consumption and low pass rate, is not considered to be environment friendly. Therefore, in this study, the sustainability of the molding process for 3D ultra thin glass was comprehensively investigated. First, the ultra thin 3D glass molding process is described, including a discussion of the glass molding apparatus, and the principle of glass thermos formation is explained. Secondly, a thermo mechanical coupling model is proposed to study the effects of loading heat and pressure on the distributions of temperature and internal stress of ultra thin glass. The results demonstrate that significant amounts of stress were concentrated at the edges, and in holes and slots. A series of experiments were conducted to reveal the respective effect of various UTGMP parameters on the energy consumption, pass rate, and carbon emission level of the process. Consequently, the percentage of the main effect of loading temperature on energy consumption was found to be 23.65% whereas that of the duration of applied pressure on the pass rate was determined to be 52.48% The optimal process parameter combinations were determined by analyzing the above mentioned research results and subsequently implementing them in a hybrid intelligent optimization algorithm that utilizes quantum behaved particle swarm optimization (QPSO) and a back propagation neural network (BPNN) The algorithm revealed that energy consumption and carbon emissions can be respectively decreased by 3.39% and 3.45% at a relatively high pass rate (i.e. over 70% Eventually, the suggested combinations for the UTGMP will be able to achieve at least 60% 76% of the pass rate, as well as consume no more than 0.756 kW h/pcs to meet sustainable manufacturing requirements. Thus, this study contributes to the effective application of a high precision glass molding process for the sustainable manufacturing of ultra thin curved glass.", "author_names": [ "Zhen Bin Zhang", "Wuyi Ming", "Yi Zhang", "Ling Yin", "Tao Xue", "Zhijun Chen", "Dunming Liao", "Guojun Zhang" ], "corpus_id": 213469658, "doc_id": "213469658", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Analyzing sustainable performance on high precision molding process of 3D ultra thin glass for smart phone", "venue": "", "year": 2020 }, { "abstract": "Glass bottles must be thoroughly inspected before they are used for packaging. However, the vision inspection of bottle bottoms for defects remains a challenging task in quality control due to inaccurate localization, the difficulty in detecting defects in the texture region, and the intrinsically nonuniform brightness across the central panel. To overcome these problems, we propose a surface defect detection framework, which is composed of three main parts. First, a new localization method named entropy rate superpixel circle detection (ERSCD) which combines least squares circle detection and entropy rate superpixel (ERS) with an improved randomized circle detection, is proposed to accurately obtain the region of interest (ROI) of the bottle bottom. Then, according to the structure property, the ROI is divided into two measurement regions: central panel region and annular texture region. For the former, a defect detection method named frequency tuned anisotropic diffusion super pixel segmentation (FTADSP) that integrates frequency tuned salient region detection (FT) anisotropic diffusion, and an improved superpixel segmentation is proposed to precisely detect the regions and boundaries of defects. For the latter, a defect detection strategy called wavelet transform multiscale filtering (WTMF) based on a wavelet transform and a multiscale filtering algorithm is proposed to reduce the influence of texture and to improve the robustness to localization error. The proposed framework is tested on four data sets obtained by our designed vision system. The experimental results demonstrate that our framework achieves the best performance compared with many traditional methods.", "author_names": [ "Xianen Zhou", "Yaonan Wang", "Qing Zhu", "Jianxu Mao", "Changyan Xiao", "Xiao Lu", "Huixia Zhang" ], "corpus_id": 201890408, "doc_id": "201890408", "n_citations": 18, "n_key_citations": 0, "score": 1, "title": "A Surface Defect Detection Framework for Glass Bottle Bottom Using Visual Attention Model and Wavelet Transform", "venue": "IEEE Transactions on Industrial Informatics", "year": 2020 }, { "abstract": "Most of previous works studied the bioactivity of tertiary soda lime borate as in vitro method, but, there have been no previous studies investigated the in vivo compatibility of such glass. This work was mainly aimed at in vivo assessment of bone formation of tertiary soda lime borate bioactive glass doped with Sr. the glass composition was based on 60 B 2 O 3 20 Na 2 O (20 x CaO x SrO (wt% where, x 0 and 10 wt% (samples encoded B0 and BS, respectively) The in vivo test was conducted in femoral bone defect of Sprague Dawley adult male rats after 3 and 6 weeks post surgery using the histological analyses and bone formation markers (alkaline phosphatase (ALP) and osteocalcin (OCN) Moreover, the possible systemic toxicity was studied using different biochemical analyses (alanine transaminase, aspartate transaminase, urea and creatinine) The result of bone markers showed that serum OCN level increased in rat implanted with sample B0 than that observed in sample BS at 3 and 6 weeks post implantation, while this finding was reversed in ALP activity. In vivo bioactivity test showed that implantation of all borate glasses did not demonstrate local or general complications in all rats, and they exhibited nearly complete bone mineralization. However, BS glass was formed more new bone than B0 one in long implantation time. In conclusion, the synthesized bioactive borate glasses were safe materials, and introducing of Sr in the glass was enhanced formation of new bone throughout long time of implantation. Accordingly, this glass can be used as a potential substitute for bone regenerative materials and a hosting for strontium ions delivery.", "author_names": [ "Zainab M Al-Rashidy", "Areg E Omar", "Tamer H Abd El-Aziz", "Mohammad M Farag" ], "corpus_id": 218528037, "doc_id": "218528037", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "In vivo bioactivity assessment of strontium containing soda lime borate glass implanted in femoral defect of rat", "venue": "Journal of Inorganic and Organometallic Polymers and Materials", "year": 2020 }, { "abstract": "Abstract Currently, the shear pre tension coupling behavior and evolution of various mesoscopic defects for the biaxial non crimp fabric (NCF) are not revealed. Here, this work systematically conducted the picture frame shear with applied pre tension and hemisphere forming for the 45deg and 0/90deg glass NCF. In the picture frame shearing, it is identified that the effective shear response of the biaxial NCF in the positive shear mode should be characterized in the cycle 1 due to the irreversible destruction of the NCF architecture. Besides, the applying pre tension is originally demonstrated to be capable of effectively suppressing the wrinkle defect and delaying the triggering shear angle of the wrinkle. Moreover, for the 45deg NCF, the stitching thread suffers tension in positive shear mode, and the wrinkle is the main defect. In the negative shear mode, due to the non pure shearing at high shear angle and compression of stitching thread, the mesoscopic defects, including bending and unit cell buckling of the stitching thread, are generated. In the hemisphere forming, it is revealed that the shear deformation is certainly arose in the tensile region of the 45deg NCF due to the asymmetrical yarn shrink. The same fabric wrinkle and mesoscopic stitching thread defects are also originally identified, demonstrating the hemisphere forming is highly correlated to the large shear deformation. The results here provide a basic reference to suppress the defects in the performing process of the biaxial NCF.", "author_names": [ "Ming Mei", "Yujia He", "Xujing Yang", "Kai Wei", "Zhaoliang Qu", "Daining Fang" ], "corpus_id": 216502804, "doc_id": "216502804", "n_citations": 7, "n_key_citations": 0, "score": 0, "title": "Shear deformation characteristics and defect evolution of the biaxial 45deg and 0/90deg glass non crimp fabrics", "venue": "", "year": 2020 }, { "abstract": "The use of bone scaffolds to replace injured or diseased bone has many advantages over the currently used autologous and allogeneic options in clinical practice. This systematic review evaluates the current evidence for non cellular scaffolds containing bioactive glass on osteogenesis and angiogenesis in animal bone defect models. Studies that reported results of osteogenesis via micro CT and results of angiogenesis via Microfil perfusion or immunohistochemistry were included in the review. A literature search of PubMed, EMBASE and Scopus was carried out in November 2019 from which nine studies met the inclusion and exclusion criteria. Despite the significant heterogeneity in the composition of the scaffolds used in each study, it could be concluded that scaffolds containing bioactive glass improve bone regeneration in these models, both by osteogenic and angiogenic measures. Incorporation of additional elements into the glass network, using additives, and using biochemical factors generally had a beneficial effect. Comparing the different compositions of non cellular bioactive glass containing scaffolds is however difficult due to the heterogeneity in bioactive glass compositions, fabrication methods and biochemical additives used.", "author_names": [ "Chanuka D S Ranmuthu", "Charindu K I Ranmuthu", "Disha Singhania" ], "corpus_id": 218616617, "doc_id": "218616617", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Evaluating the Effect of Non cellular Bioactive Glass Containing Scaffolds on Osteogenesis and Angiogenesis in in vivo Animal Bone Defect Models", "venue": "Frontiers in Bioengineering and Biotechnology", "year": 2020 }, { "abstract": "Abstract Demands for display panels and relevant technologies are rapidly increasing with the recent advances in smart mobile devices. Many manufacturers have begun slowly investing in fully automated inspection systems that enable consistent and objective inspections. Carrying out such undertaking aims to satisfy high user requirements concerning quality while coping with high volumes. Cover glass is one of the important items for inspection because users directly interact with it. Despite the extensive use of typical machine vision based solutions in this field, many manufacturers continue relying on human based judgment because of a deficient understanding of defects or poor confidence in algorithms. To overcome these problems, this study proposes a deep learning neural network (DLNN) based defect inspection system. The DLNN has advantages over traditional computer vision or human based inspection in terms of flexibility and performance. We introduce a weighted multi DLNN inspection system capable of efficiently utilizing multi channel measurement data, with a detection rate of up to 99% and a false pass rate below 1%", "author_names": [ "Jisu Park", "Hamza Riaz", "Hyunchul Kim", "Jungsuk Kim" ], "corpus_id": 213469045, "doc_id": "213469045", "n_citations": 5, "n_key_citations": 0, "score": 1, "title": "Advanced cover glass defect detection and classification based on multi DNN model", "venue": "", "year": 2020 }, { "abstract": "Abstract The effect of cerium content on phase evolution, dielectric properties and defect mechanism has been investigated in (Ba,Sr)TiO3 glass ceramics. Cerium mainly acts as an isovalent dopant in the B site of ABO3 perovskite structure at low content (1 mol% and then cerium substitution gradually occurs in the A site with increasing cerium content. A compensation mechanism related to variation in oxygen vacancy concentration has been identified. When cerium content increased to 2 mol% the maximum values of dielectric constant and energy storage density were simultaneously achieved. The impedance spectra revealed the highest conductivity. It was due to the increase in the concentration of charge carriers accompanied by the decrease in the activation energy of oxygen vacancy migration. With a further addition of cerium to 3 mol% the opposite trend was observed. The result is related to the presence of more cation vacancies, which, in turn, limits the diffusion rate of oxygen vacancy.", "author_names": [ "Zhangyuan Zhao", "Xuewei Liang", "Tianyuan Zhang", "Kangjia Hu", "Shenhou Li", "Yue-fei Zhang" ], "corpus_id": 210804231, "doc_id": "210804231", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Effects of cerium doping on dielectric properties and defect mechanism of barium strontium titanate glass ceramics", "venue": "", "year": 2020 } ]
amorphous polycrystalline solar panel spectral response
[ { "abstract": "Quantum dot solar cells are based on the concept of harvesting different parts of the solar light spectrum with a single, cheap semiconductor by simply changing the size of the nanoparticles. Of th.", "author_names": [ "Jacopo Parravicini", "Francesco Di Trapani", "Michael D Nelson", "Zachary T Rex", "Ryan Beiter", "Tiziano Catelani", "Maurizio Acciarri", "Alessandro Podesta", "Cristina Lenardi", "Simona Binetti", "Marcel Di Vece" ], "corpus_id": 214065245, "doc_id": "214065245", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Quantum Confinement in the Spectral Response of n Doped Germanium Quantum Dots Embedded in an Amorphous Si Layer for Quantum Dot Based Solar Cells", "venue": "", "year": 2020 }, { "abstract": "Spectral response and diffusion length characteristics of the various MIS cells developed at Rutgers and previously reported in the literature have been investigated. The cells, designated according to the type of Si substrate used, appear in the following descending order based on the above studies: (1) Monsanto single crystal Si with a peak quantum efficiency (QE) of 87.4% and a diffusion length (Ln) of 70 mm, (2) Wacker polycrystalline Si, peak QE=82.8% Ln=60 mm, (3) IBM ribbon Si, (4) epitaxial Si, (5) Mobil Tyco EFG ribbon Si, and (6) amorphous Si (Plasma Physics Corp. Theoretical plots of quantum efficiency and short circuit current density are shown to be in reasonable agreement with experimental results. The enhanced ultraviolet response of the MIS cell compared to that of a commercial N/P junction cell is demonstrated even though the latter device has a peak QE of almost 100% and an Ln value of 184 mm. The spectral studies lend support to the conclusions derived from the previously measured el.", "author_names": [ "Sandwip K Dey", "William A Anderson", "Alan E Delahoy", "Christophe Cartier" ], "corpus_id": 121749374, "doc_id": "121749374", "n_citations": 9, "n_key_citations": 0, "score": 1, "title": "Spectral response and diffusion length studies of amorphous, polycrystalline, ribbon, epitaxial, and single crystal silicon MIS solar cells", "venue": "", "year": 1979 }, { "abstract": "Reactive ion etching technology was combined with passivated emitter rear cell technology to reduce the reflectance and transmittance of incident light and improve the spectral response of polycrystalline silicon solar cell. Preconditioning with acid solution can induce the formation of worm like structures on the front surface, which could bring about the reduction of reflectance and enhancement of spectral response in the visible range. Optimization of the capping layer thickness on the rear side can enhance the internal reflection, which will decrease the transmittance and promote the spectral response in long wavelength range.", "author_names": [ "Shude Zhang", "Hongqiang Qian", "Jiaqi Peng", "Qingzhu Wei", "Zhichun Ni" ], "corpus_id": 54444337, "doc_id": "54444337", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Spectral Response Optimization of Polycrystalline Black Silicon Solar Cell by Reactive Ion Etching Combined with PERC Technology", "venue": "2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC 34th EU PVSEC)", "year": 2018 }, { "abstract": "The heterojunction silicon solar cells displaying two different open circuit voltages and having S shape light current density voltage characteristics are analyzed by observing change in quantum efficiency (QE) with voltage and light bias conditions. With forward bias voltage close to (and beyond) the S shape region, the QE is reduced uniformly in all the regions, due to dominance of barrier over junction field for collection of holes. Under white light bias along with the voltage biasing close to the S shape characteristics, an improvement of QE is observed due to saturation of defects at the interface and enhancement of photoconductivity of the amorphous Si layers. The cell with small open circuit voltage showed considerable improvement in QE from interfacial region (e.g. in the short and long wavelength region) while response in the bulk region (intermediate wavelength region) remains flat.", "author_names": [ "Sapna Mudgal", "Son Pal Singh", "Vamsi Krishna Komarala" ], "corpus_id": 54214415, "doc_id": "54214415", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Interfacial spectral response under voltage and light bias to analyse low voltage in amorphous crystalline silicon heterojunction solar cell with S shape characteristics", "venue": "2018 IEEE 7th World Conference on Photovoltaic Energy Conversion (WCPEC) (A Joint Conference of 45th IEEE PVSC, 28th PVSEC 34th EU PVSEC)", "year": 2018 }, { "abstract": "Spectral response and diffusion length characteristics of the various MIS cells developed at Rutgers and previously reported in the literature have been investigated. The cells, designated according to the type of Si substrate used, appear in the following descending order based on the above studies: (1) Monsanto single crystal Si with a peak quantum efficiency (Q.E. of 87.4% and a diffusion length (Ln) of 70 um, (2) Wacker polycrystalline Si, peak Q.E. 82.8% Ln= 60 um, (3) IBM ribbon Si, (4) Epitaxial Si, (5) Mobil Tyco EFG ribbon Si and (6) amorphous Si. The Q.E. of the Monsanto Si base line cell is shown to be adequately explained in terms of the wavelength dependence of the collection efficiency and the transmittance of the barrier metal. Good agreement is also shown between theoretical and experimental plots of short circuit current density (Jsc) versus Ln. The Wacker cell shows best short wavelength response of all the cells studied including a commercial p n cell having a peak Q.E. of 100% and Ln= 184 um.", "author_names": [ "Sandwip K Dey", "William A Anderson", "Alan E Delahoy", "Christophe Cartier" ], "corpus_id": 22229, "doc_id": "22229", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Relating photovoltaic output and spectral response of amorphous, polycrystalline, ribbon, epitaxial and single crystal MIS solar cells", "venue": "1978 International Electron Devices Meeting", "year": 1978 }, { "abstract": "The seasonal variations of solar photovoltaic cells photocurrent under cloudless conditions are analyzed. This analysis is done by using models of the absorption of solar radiation in the atmosphere and the spectral response of various types of solar cells. The problems of determining the atmospheric model parameters for calculating seasonal variations in absorption are indicated. A simple model that describes the effects of degradation and regeneration of photosensitive material is proposed to describe peculiarities of seasonal variations in the photocurrent of amorphous silicon cells.", "author_names": [ "A L Bozhenko", "Yuri Y Dymytrov", "Vladimir I Kubov", "R M Kubova" ], "corpus_id": 218563902, "doc_id": "218563902", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "The Photovoltaic Cells Spectral Response and Photocurrent Seasonal Variations", "venue": "2020 IEEE 40th International Conference on Electronics and Nanotechnology (ELNANO)", "year": 2020 }, { "abstract": "Abstract In this paper, high temperature solar blind photodetectors were fabricated based on polycrystalline Ga2O3 (poly Ga2O3) film which was prepared by annealing amorphous Ga2O3 (a Ga2O3) film in oxygen atmosphere. The effects of annealing temperature on the properties of the material and the performances of the corresponding Metal semiconductor metal photodetector were investigated. The main factors affecting device performance are attributed to the oxygen vacancy defect concentration in Ga2O3 and the effective Schottky barrier height and width between gold and Ga2O3. We found that the detector based on 650 degC annealed poly Ga2O3 showed the best solar blind detection photoelectric performance and good thermal stability. More interestingly, the device has fast response recovery speed (0.16 s) low dark current =0.1 nA) and high photo to dark current ratio =97) at 200 degC high temperature operation. These performances are even better than the reported high temperature photodetectors based on high quality crystal Ga2O3 thin film or Ga2O3 bulk. Besides, our method that avoid direct high temperature growth of poly Ga2O3 and may be beneficial to its commercial large area production and further cost reduction.", "author_names": [ "Hai-tao Zhou", "Lujia Cong", "Jiangang Ma", "Ming-Zhu Chen", "Dongyu Song", "Hong-bin Wang", "Peng Li", "Bingsheng Li", "Haiyang Xu", "Yi-chun Liu" ], "corpus_id": 225154731, "doc_id": "225154731", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "High performance high temperature solar blind photodetector based on polycrystalline Ga2O3 film", "venue": "", "year": 2020 }, { "abstract": "Abstract An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2 4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.", "author_names": [ "J A Rodriguez", "Montserrat Fortes", "Cesar Alberte", "Michael Vetter", "Jordi S Andreu" ], "corpus_id": 97471514, "doc_id": "97471514", "n_citations": 16, "n_key_citations": 1, "score": 0, "title": "Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules", "venue": "", "year": 2013 }, { "abstract": "Solar blind photodetectors are critically important for civil and military applications. Several of these applications, such as space exploration and nuclear energy infrastructure, demand the use of a photodetector under extreme environments. In this paper, we have studied the radiation hardness and device performance of amorphous and polycrystalline gallium oxide thin films against heavy ion (Ag7+ irradiation with a high energy of 100 MeV. Gallium oxide thin films show great tenacity against massive and highly energetic ions. The amorphous and polycrystalline phases undergo structural and morphological changes that initially induce degradation in the device performance. Nano pore like structures are formed in the amorphous film, while the polycrystalline film shows the destruction of large crystallites. The responsivity of the photodetector device reduces fourfold in the amorphous phase; however, a sixfold reduction in the performance is observed in the polycrystalline phase of the gallium oxide photodetector. The degradation is attributed to the annealing of pre existing optical defects that are otherwise responsible for the huge photoconductive gain in the detector and confirmed by photoluminescence studies. The effect of self annealing at room temperature and annealing at moderate temperature is investigated to recover the irradiated photodetector devices. Partial recovery in the polycrystalline based photodetector and two orders of magnitude enhanced responsivity and an almost twice faster response time compared to the control photodetectors in the amorphous phase are observed. This work investigates the effect of heavy and energetic ions on the performance of gallium oxide based solar blind photodetector and provides the guideline to use high energy irradiation as a tool for defect engineering.", "author_names": [ "Damanpreet Kaur", "Pargam Vashishtha", "Saif A Khan", "Pawan Kumar Kulriya", "Govind Gupta", "Mukesh Kumar" ], "corpus_id": 225493587, "doc_id": "225493587", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Phase dependent radiation hardness and performance analysis of amorphous and polycrystalline Ga2O3 solar blind photodetector against swift heavy ion irradiation", "venue": "", "year": 2020 }, { "abstract": "Abstract We employed the low temperature hydrogenated amorphous silicon nitride (a SiN x :H) prepared by plasma enhanced chemical vapor deposition as a refractive index n matching layers in a silicon based thin film solar cell between glass n 1.5) and the transparent conducting oxide n 2) By varying the stoichiometry, refractive index and thickness of the a SiN x :H layers, we enhanced the spectral response and efficiency of the hydrogenated amorphous silicon thin film solar cells. The refractive index of a SiN x :H was reduced from 2.32 to 1.78. Optimizing the a SiN x :H thickness to 80 nm increased the J SC from 8.3 to 9.8 mA/cm 2 and the corresponding cell efficiency increased from 4.5 to 5.3% as compared to the cell without the a SiN x :H index matching layer on planar substrate. The a SiN x :H layers with graded refractive indices were effective for enhancing the cell performance.", "author_names": [ "Ching-Yi Hsu", "Y P Lin", "Hung-Jung Hsu", "Chin-Chung Tsai" ], "corpus_id": 56156245, "doc_id": "56156245", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Enhanced spectral response by silicon nitride index matching layer in amorphous silicon thin film solar cells", "venue": "", "year": 2012 } ]
WAFER classification
[ { "abstract": "Silicon wafer is the most crucial material in the semiconductor manufacturing industry. Owing to limited resources, the reclamation of monitor and dummy wafers for reuse can dramatically lower the cost, and become a competitive edge in this industry. However, defects such as void, scratches, particles, and contamination are found on the surfaces of the reclaimed wafers. Most of the reclaimed wafers with the asymmetric distribution of the defects, known as the \"good (G)\" reclaimed wafers, can be re polished if their defects are not irreversible and if their thicknesses are sufficient for re polishing. Currently, the \"no good (NG)\" reclaimed wafers must be first screened by experienced human inspectors to determine their re usability through defect mapping. This screening task is tedious, time consuming, and unreliable. This study presents a deep learning based reclaimed wafers defect classification approach. Three neural networks, multilayer perceptron (MLP) convolutional neural network (CNN) and Residual Network (ResNet) are adopted and compared for classification. These networks analyze the pattern of defect mapping and determine not only the reclaimed wafers are suitable for re polishing but also where the defect categories belong. The open source TensorFlow library was used to train the MLP, CNN, and ResNet networks using collected wafer images as input data. Based on the experimental results, we found that the system applying CNN networks with a proper design of kernels and structures gave fast and superior performance in identifying defective wafers owing to its deep learning capability, and the ResNet averagely exhibited excellent accuracy, while the large scale MLP networks also acquired good results with proper network structures.", "author_names": [ "Po-Chou Shih", "Chun-Chin Hsu", "F C Tien" ], "corpus_id": 219071734, "doc_id": "219071734", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Automatic Reclaimed Wafer Classification Using Deep Learning Neural Networks", "venue": "Symmetry", "year": 2020 }, { "abstract": "", "author_names": [ "Hyun-Jin Kim", "Kwan-Young Bak", "Jae-Kyung Shin", "Ja-Yong Koo" ], "corpus_id": 216168421, "doc_id": "216168421", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Functional Logistic Regression based on Constant Splines for Wafer Classification", "venue": "", "year": 2020 }, { "abstract": "A wafer bin map (WBM) which is the result of an electrical die sorting test, provides information on which bins failed what tests, and plays an important role in finding defective wafer patterns in semiconductor manufacturing. Current wafer inspection based on WBM has two problems: good/bad WBM classification is performed by engineers and the bin code coloring scheme does not reflect the relationship between bin codes. To solve these problems, we propose a neural network based bin coloring method called Bin2Vec to make similar bin codes are represented by similar colors. We also build a convolutional neural network based WBM classification model to reduce the variations in the decisions made by engineers with different expertise by learning the company wide historical WBM classification results. Based on a real dataset with a total of 27,701 WBMs, our WBM classification model significantly outperformed benchmarked machine learning models. In addition, the visualization results of the proposed Bin2Vec method makes it easier to discover meaningful WBM patterns compared with the random RGB coloring scheme. We expect the proposed framework to improve both efficiencies by automating the bad wafer classification process and effectiveness by assigning similar bin codes and their corresponding colors on the WBM.", "author_names": [ "Junhong Kim", "Hyungseok Kim", "Jaesun Park", "Kyounghyun Mo", "Pilsung Kang" ], "corpus_id": 116259654, "doc_id": "116259654", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Bin2Vec: A Better Wafer Bin Map Coloring Scheme for Comprehensible Visualization and Effective Bad Wafer Classification", "venue": "Applied Sciences", "year": 2019 }, { "abstract": "In the semiconductor manufacturing process, it is important to identify wafers on which faults have occurred or will occur to avoid unnecessary and costly further processing and physical inspections. This issue can be addressed by formulating the faulty wafer detection problem as a predictive modeling task, in which the process parameters/measurements and subsequent inspection results concerning the faults comprise the input and output variables at the wafer level, respectively. To achieve improved predictive performance, this paper presents a joint modeling method that incorporates classification and regression tasks into a single prediction model. Given the output variables in both binary and continuous forms, the prediction model simultaneously considers both the classification and regression tasks to complement each other, where each task predicts the binary and continuous output variables, respectively. The outputs from these two tasks are combined to predict whether a wafer is faulty. The entire model is implemented as a neural network, and is trained by optimizing a single objective function. The effectiveness of the model is demonstrated with a case study using real world data from a semiconductor manufacturer.", "author_names": [ "Seokho Kang" ], "corpus_id": 115997705, "doc_id": "115997705", "n_citations": 11, "n_key_citations": 1, "score": 0, "title": "Joint modeling of classification and regression for improving faulty wafer detection in semiconductor manufacturing", "venue": "J. Intell. Manuf.", "year": 2020 }, { "abstract": "Wafer map analysis provides critical information for quality control and yield improvement tasks in semiconductor manufacturing. In particular, wafer patterns of gross failing areas (GFA) are important clues to identify the causes of relevant failures during the manufacturing process. In this work, a semi supervised classification framework is proposed for wafer map analysis, and its application to wafer bin maps with GFA patterns classification is demonstrated. The Ladder network and the semi supervised variational autoencoder are adopted to classify wafer bin maps in comparison with a standard convolutional neural network (CNN) model on two real world datasets. The results have illustrated that two semi supervised models are consistently and substantially better than the CNN model across various training data percentages by effective utilization of the unlabeled data. Active learning and pseudo labeling are also utilized to accelerate the learning curve.", "author_names": [ "Yuting Kong", "Dong Ni" ], "corpus_id": 211055625, "doc_id": "211055625", "n_citations": 9, "n_key_citations": 1, "score": 1, "title": "A Semi Supervised and Incremental Modeling Framework for Wafer Map Classification", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2020 }, { "abstract": "Defect clusters on the wafer map can provide important clue to identify the process failures so that it is important to accurately classify the defect patterns into corresponding pattern types. In this research, we present an image based wafer map defect pattern classification method. The presented method consists of two main steps: without any specific preprocessing, high level features are extracted from convolutional neural network and then the extracted features are fed to combination of error correcting output codes and support vector machines for wafer map defect pattern classification. To the best of our knowledge, no prior work has applied the presented method for wafer map defect pattern classification. Experimental results tested on 20,000 wafer maps show the superiority of presented method and the overall classification accuracy is up to 98.43%", "author_names": [ "Cheng Hao Jin", "Hyun-Jin Kim", "Yongjun Piao", "Meijing Li", "Minghao Piao" ], "corpus_id": 213671935, "doc_id": "213671935", "n_citations": 9, "n_key_citations": 1, "score": 0, "title": "Wafer map defect pattern classification based on convolutional neural network features and error correcting output codes", "venue": "J. Intell. Manuf.", "year": 2020 }, { "abstract": "An automatic defect classification (ADC) system identifies and classifies wafer surface defects using scanning electron microscope images. By classifying defects, manufacturers can determine whether the wafer can be repaired and proceed to the next fabrication step. Current ADC systems have high defect detection performance. However, the classification power is poor. In most work sites, defect classification is performed manually using the naked eye, which is unreliable. This paper proposes an ADC method based on deep learning that automatically classifies various types of wafer surface damage. In contrast to conventional ADC methods, which apply a series of image recognition and machine learning techniques to find features for defect classification, the proposed model adopts a single convolutional neural network (CNN) model that can extract effective features for defect classification without using additional feature extraction algorithms. Moreover, the proposed method can identify defect classes not seen during training by comparing the CNN features of the unseen classes with those of the trained classes. Experiments with real datasets verified that the proposed ADC method achieves high defect classification performance.", "author_names": [ "Sejune Cheon", "Hankang Lee", "Chang Ouk Kim", "Seok Hyung Lee" ], "corpus_id": 116334837, "doc_id": "116334837", "n_citations": 52, "n_key_citations": 1, "score": 0, "title": "Convolutional Neural Network for Wafer Surface Defect Classification and the Detection of Unknown Defect Class", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2019 }, { "abstract": "Increasing yield is a primary concern to integrated circuit manufacturing companies as it dictates the readiness of a new process for high volume manufacturing. In order to expedite the process of discovering yield issues, companies have started looking for ways to perform early prediction for such issues. This paper suggests the use of the support vector machines (SVMs) for early wafer classification. The choice of SVM is motivated by the model's ability to effectively classify multivariate, multimodal, and inseparable data points. This model uses multidimensional hyperplanes to separate and classify wafers into low yield and high yield classes. This paper includes a proposal for how the classification model can be applied for yield classification and how it can be adaptively updated in a manufacturing environment. We show how the values for the SVM parameters can be selected for best yield classification. Furthermore, performance evaluation is conducted on real manufacturing data, comparing the proposed SVM classifier to state of the art. Results show that in all cases, SVM consistently outperforms other methods with and without adaptive model updates. The experiments also show that all classifiers' performances depend on yield thresholds. It is also shown that the classification model can be built and executed using a reduced set without compromising its accuracy.", "author_names": [ "R Baly", "Hazem Hajj" ], "corpus_id": 35786120, "doc_id": "35786120", "n_citations": 64, "n_key_citations": 5, "score": 0, "title": "Wafer Classification Using Support Vector Machines", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2012 }, { "abstract": "In the semiconductor industry, the testing section has always played an important role. The testing section often requires engineers to judge the defect, which wastes a lot of time and cost. The accurate classification can provide useful information for engineers through neural networks. In this paper, we present a method for wafer map data augmentation and defect classification. Data augmentation is based on CNN encoder decoder and the classification is based on depthwise separable convolutions. There are two datasets used, one is open dataset WM 811K and the other is built with a Taiwan company. We train two models with mobilenetV1 and V2 for the different datasets. The light weight deep convolution can reduce model parameters and calculations, which is very efficient for the testing house with large production volumes. On two different data sets, our proposed method can reduce the number of parameters by 30% and 95% and reduce the amount of calculation by 75% and 25% respectively. The test accuracy of the first dataset is 93.95% The second dataset test accuracy is 87.04% After the data augmentation, accuracy is increased to 97.01% and 95.09% respectively.", "author_names": [ "Tsung-Han Tsai", "Yu-Chen Lee" ], "corpus_id": 226293968, "doc_id": "226293968", "n_citations": 6, "n_key_citations": 1, "score": 1, "title": "A Light Weight Neural Network for Wafer Map Classification Based on Data Augmentation", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2020 }, { "abstract": "Wafer maps provide important information for engineers for detecting root causes of failure in a semiconductor manufacturing process. Thus, there has been active research into the automation of wafer map pattern classification. With recent advances in deep learning, a convolutional neural network (CNN) has yielded state of the art performance in wafer map pattern classification. Because a large amount of labeled training data is required, experienced engineers need to annotate large quantities of wafer maps manually which is costly. To construct a well performing CNN model with a lower labeling cost, we propose a cost effective wafer map pattern classification system based on the active learning of a CNN. In the system, a CNN model is constructed based on four main steps: uncertainty estimation, query wafer selection, query wafer labeling, and model update. By repetitively performing these steps, the performance of the CNN model is gradually and effectively increased. We compared several methods for uncertainty estimation and query wafer selection in our system. We demonstrated the effectiveness of the proposed system through experiments using real world data from a semiconductor manufacturer.", "author_names": [ "Jaewoong Shim", "Seokho Kang", "Sungzoon Cho" ], "corpus_id": 214281189, "doc_id": "214281189", "n_citations": 8, "n_key_citations": 0, "score": 0, "title": "Active Learning of Convolutional Neural Network for Cost Effective Wafer Map Pattern Classification", "venue": "IEEE Transactions on Semiconductor Manufacturing", "year": 2020 } ]
applied physics letters ,104,21917(2014)
[ { "abstract": "Chuan Liu, Yong Xu, Gerard Ghibaudo, Xubing Lu, Takeo Minari, and Yong Young Noh Citation: Applied Physics Letters 104, 079902 (2014) doi: 10.1063/1.4866287 View online: http:/dx.doi.org/10.1063/1.4866287 View Table of Contents: http:/scitation.aip.org/content/aip/journal/apl/104/7?ver=pdfcov Published by the AIP Publishing Articles you may be interested in Evaluating injection and transport properties of organic field effect transistors by the convergence point intransfer length method Appl. Phys. Lett. 104, 013301 (2014) 10.1063/1.4860958 Erratum: \"Influence of dielectric dependent interfacial widths on device performance in top gate P(NDI2OD T2)field effect transistors\" [Appl. Phys. Lett.101, 093308 (2012) Appl. Phys. Lett. 101, 179901 (2012) 10.1063/1.4762831 Erratum: \"Poly(3 hexylthiophene) crystalline nanoribbon network for organic field effect transistors\" [Appl. Phys.Lett.96, 243304 (2010) Appl. Phys. Lett. 97, 189902 (2010) 10.1063/1.3512957 Comment on \"Depletion width measurement in an organic Schottky contact using a metal semiconductor field effect transistor\" [Appl. Phys. Lett.91, 083513 (2007) Appl. Phys. Lett. 97, 096101 (2010) 10.1063/1.3475395 Erratum: \"Electronic transport characteristics of electrolyte gated conducting polyaniline nanowire field effecttransistors\" [Appl. Phys. Lett.95, 013113 (2009) Appl. Phys. Lett. 95, 079901 (2009) 10.1063/1.3213393", "author_names": [ "Chuan Liu", "Yong Xu", "Gerard Ghibaudo", "Xubing Lu", "Takeo Minari", "Yong-Young Noh" ], "corpus_id": 121484367, "doc_id": "121484367", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Erratum: \"Evaluating injection and transport properties of organic field effect transistors by the convergence point in transfer length method\" [Appl. Phys. Lett. 104, 013301 (2014)", "venue": "", "year": 2014 }, { "abstract": "Enhanced flexoelectricity in perovskite ceramics and single crystals has been reported before. In this letter, 3 3 ceramic ceramic Ba0.6Sr0.4TiO3/Ni0.8Zn0.2Fe2O4 composite with a colossal permittivity was employed in the conventional pure bending experiment in order to examine the transverse flexoelectric response. The measured flexoelectric coefficient at 30 Hz is 128 mC/m and varies to 16 mC/m with the frequency increasing from 30 Hz to 120 Hz, mainly due to the inverse correlation between the permittivity and the frequency. This result reveals the permittivity dependence of flexoelectric coefficient in the frequency dispersion materials, suggesting that the giant permittivity composites can be good flexoelectric materials. Disciplines Engineering Physical Sciences and Mathematics Publication Details Shu, L. Huang, W. Kwon, S. Ryung. Wang, Z. Li, F. Wei, X. Zhang, S. Lanagan, M. Yao, X. Jiang, X. (2014) Converse flexoelectric coefficient f(1212) in bulk Ba0.67Sr0.33TiO3. Applied Physics Letters, 104 (23) 232902 1 232902 6. Authors Longlong Shu, Wenbin Huang, Seol Ryung Kwon, Zhao Wang, Fei Li, Xiaoyong Wei, Shujun Zhang, Michael T. Lanagan, Xi Yao, and Xiaoning Jiang This journal article is available at Research Online: http:/ro.uow.edu.au/aiimpapers/3070 Converse flexoelectric coefficient f1212 in bulk Ba0.67Sr0.33TiO3 Longlong Shu, Wenbin Huang, Seol Ryung Kwon, Zhao Wang, Fei Li, Xiaoyong Wei, Shujun Zhang, Michael Lanagan, Xi Yao, and Xiaoning Jiang Citation: Appl. Phys. Lett. 104, 232902 (2014) doi: 10.1063/1.4882060 View online: https:/doi.org/10.1063/1.4882060 View Table of", "author_names": [ "Longlong Shu", "Wenbin Huang", "Seol ryung Kwon", "Zu-Jun Wang", "Fei Li", "Xiaoyong Wei", "Shujun Zhang", "Michael T Lanagan", "Xi Yao", "Xiaoning Jiang" ], "corpus_id": 54707747, "doc_id": "54707747", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "Converse flexoelectric coefficient f 1212 in bulk Ba 0 67 Sr 0 33 TiO 3", "venue": "", "year": 2014 }, { "abstract": "A thin film based Erbium doped Tellurium Oxide (TeO2) waveguide amplifier producing gain from 1500nm to 1640nm when pumped at 980nm is demonstrated. At measured internal gains exceeding 14dB lasing due to end facet reflection set in producing the first tellurite waveguide laser. High gains were observed despite significant upconversion, whose impact appears to be mitigated to some extent by residual OH contamination. The device displayed no photosensitive effects from either the high pumping intensities used or the intracavity intensity at 1550nm. (c)2014 Optical Society of America OCIS codes: (130.3120) Integrated optics devices; (140.3210) Laser amplifier; (160.4670) Optical materials; (230.7370) Waveguides. References and links 1. S. Berneschi, G. Nunzi Conti, G.C. Righini, \"Planar waveguide ampflifiers,\" Ceramist: Jnl Korean Ceram. Soc. 10, 75 85 (2007) 2. G.N. van den Hoven, R.J.I.M. Koper, A. Polman, C. van Dam, J.W.M. van Uffelen, M.K. Smit, \"Net optical gain at 1.53 mm in Er doped Al2O3 waveguides on silicon,\" Applied Physics Letters 68, 1886 1888 (1996) 3. J.E. Roman, M. Hempstead, C. Ye, S. Nouh, P. Camy, P. Laborde, C. Lerminiaux, \"1.7 mm excited state absorption measurement in erbium doped glasses,\" Appl. Phys. Lett. 67, 470 472 (1995) 4. Y.C. Yan, A.J. Faber, H. de Waal, P.G. Kik, A. Polman, \"Erbium doped phosphate glass waveguide on silicon with 4.1 dB/cm gain at 1.535 m,\" Applied Physics Letters 71, 2922 2922 (1997) 5. G. Della Valle, A. Festa, G. Sorbello, K. Ennser, C. Cassagnetes, D. Barbier, S. Taccheo, \"Single mode and high power waveguide lasers fabricated by ion exchange,\" Opt. Express 16, 12334 12341 (2008) 6. G. Della Valle, R. Osellame, G. Galzerano, N. Chiodo, G. Cerullo, P. Laporta, O. Svelto, U. Morgner, A.G. Rozhin, V. Scardaci, A.C. Ferrari, \"Passive mode locking by carbon nanotubes in a femtosecond laser written waveguide laser,\" Applied Physics Letters 89 (2006) 7. G. Della Valle, S. Taccheo, P. Laporta, G. Sorbello, E. Cianci, V. Foglietti, \"Compact high gain Erbiumytterbium doped waveguide amplifier fabricated by Ag Na ion exchange,\" Electronics Letters 42, 632 633 (2006) 8. R. Osellame, G. Della Valle, N. Chiodo, S. Taccheo, P. Laporta, O. Svelto, G. Cerullo, \"Lasing in femtosecond laser written optical waveguides,\" Applied Physics A: Materials Science Processing 93, 17 26 (2008) 9. R.A.H. El Mallawany, Tellurite glasses handbook: physical properties and data (CRC Press, US, 2002) 10. C.E. Chryssou, F. Di Pasquale, C.W. Pitt, \"Er doped channel optical waveguide amplifiers for WDM systems: A comparison of tellurite, alumina and Al/P silicate materials,\" IEEE Journal on Selected Topics in Quantum Electronics 6, 114 121 (2000) 11. S. Dai, C. Yu, G. Zhou, J. Zhang, G. Wang, L. Hu, \"Concentration quenching in Erbium doped tellurite glasses,\" Journal of Luminescence 117, 39 45 (2006) 12. A. Mori, \"Tellurite based fibers and their applications to optical communication networks,\" Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan 116, 1040 1051 (2008) 13. S. Shen, A. Jha, X. Liu, M. Naftaly, K. Bindra, H.J. Bookey, A.K. Kar, \"Tellurite glasses for broadband amplifiers and integrated optics,\" J Am Ceram Soc 85, 1391 1395 (2002) 14. T.T. Fernandez, G. Della Valle, R. Osellame, G. Jose, N. Chiodo, A. Jha, P. Laporta, \"Active waveguides written by femtosecond laser irradiation in an Erbium doped phospho tellurite glass,\" Optics Express 16, 15198", "author_names": [ "Khu Vu", "Sajjad Farahani", "Steve J Madden" ], "corpus_id": 40417287, "doc_id": "40417287", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "980 nm pumped Erbium Doped Tellurium Oxide Planar Rib Waveguide Laser and Amplifier with Gain in S C and", "venue": "", "year": 2014 }, { "abstract": "Zai Guang Dian Dui Kang Ying Yong Zhong ,2.7 mmHe 4.3 mmBo Duan De Shuang Zhong Hong Wai Ji Guang Shou Dao Te Bie Guan Zhu Qi Jin Yi You De Ji Zhu Tu Jing Du Zhi Neng Fen Bie Chan Sheng Qi Zhong Yi Ge Bo Duan De Ji Guang ,Qie Chan Sheng Fang Fa Dan Yi Zhuan Huan Xiao Lu Shou Dao Yi Ding Xian Zhi Xin Jin Yan Jiu Biao Ming ,Ru Guo Cai Yong Te Ding Bo Chang 1.658 mmDe Ji Guang Zuo Wei Beng Pu Guang Yuan ,Tong Guo Fei Xian Xing Can Liang Guo Cheng ,Ke Yi Tong Shi Huo De 2.7 mm, 4.3 mmLiang Ge You Yong Bo Duan De Ji Guang Shu Chu Shuang Zhong Hong Wai Ji Guang Fang An De Nan Dian He Guan Jian Zai Yu 1.658 mmZhe Ge Te Ding Bo Chang Shi Qian Suo Wei You De Bu Neng You Xi Tu Chi Zi Zhi Jie Fu She Chan Sheng Ling Yi Ge Te Shu Bo Duan Ji Guang Ying Yong De Lei Si Li Zheng Wei :Zai Da Qi Tuan Liu Zi Gua Ying Guang Xue Bo Qian Xiao Zheng Xi Tong Zhong ,Na Dao Xing De Xin Biao Guang Yuan Suo Xu De 589.1591 nmZhai Dai Huang Guang Ji Guang (Dui Ying Na Yuan Zi D2Pu Xian )Ye Shi Yi Ge Chang Gui Fang Fa Bu Neng Zhi Jie Chan Sheng De Te Ding Bo Chang Yin Ci ,Yan Jiu Jie Jue Chan Sheng Ge Lei Te Ding Bo Chang Ji Guang De Ji Zhu Tu Jing He Fang Fa ,Shi Shi Fen Bi Yao He You Yi Yi De Zuo Wei Dian Xing Shi Li ,Ben Lun Wen Jiang Zhu Yao Zhen Dui 1.6 mmBo Duan De Xu Qiu ,Kai Zhan Xi Tong De Li Lun He Shi Yan Yan Jiu Zai Li Lun Yan Jiu Ji Chu Shang ,Ti Chu Bing You Hua She Ji Liao Yi Tiao Ju You Pu Gua Yi Yi De Ji Lian Xing Ji Zhu Lu Xian Zhai Xian Kuan 1.5 mm Er:YbGong Xian Guang Xian Ji Guang Beng Pu 1.6 mmBo Duan La Man Guang Xian Ji Guang Qi ;Zai Shi Yan Shang Cheng Gong Shi Xian Liao Fu Gai 1.5, 1.6 mmBo Duan De Zhai Dai Ke Diao Xie Ji Bo Chang Suo Ding Ji Guang Shu Chu Huo De Fa Ming Zhuan Li Shou Quan Tong Guo Gai Bian Zeng Yi Guang Xian Chang Du ,Bing Yun Yong Ti Bu La Ge Guang Zha (VBG)Bo Chang Diao Xie ,Shou Ci Zai Er:YbGong Xian Guang Xian Ji Guang Qi Zhong Huo De Liao Tong Shi Fu Gai C bandHe L bandDe Ke Diao Xie Ji Guang Shu Chu ;Yun Yong Shuang VBGGuang Pu Zhai Hua Ji Zhu ,Huo De Liao Tong Lei Ji Zhu Zui Zhai Xian Kuan Xiao Yu ~38 pmHe 19.4 WGong Lu De Ji Guang Shu Chu Zai Yi Zhai Dai 1545 nm Er:YbGong Xian Guang Xian Ji Guang Beng Pu Jian Bian Zhe She Lu Duo Mo Tong Xin Guang Xian He Te Shu She Ji De Shuang Bao Ceng La Man Guang Xian ,Ying Yong VBGYu Bo Chang Diao Xie Bo Chang Suo Ding Ji Guang Pu Zhai Hua ,Shi Xian Liao 1.6 mmBo Duan 10.5 WGong Lu Tong Lei Ji Zhu Zui Zhai Xian Kuan 0.1 nmDe Ji Guang Shu Chu He Zui Da 37 nmDe Diao Xie Fan Wei ;Chan Shu Liao La Man Guang Xian Zhong SRSDe Guang Shu Jing Hua Zuo Yong ,Huo De Jin Yan She Ji Xian De StokesJi Guang Shu Chu Lun Wen Qu De Yi Xi Lie Chuang Xin Cheng Guo ,Fa Biao Liao Duo Pian Lun Wen Bao Gao ,Bao Gua SCILun Wen 5Pian EILun Wen 1Pian Xue Zhu Hui Yi Bao Gao 2Pian ,Yi Ji Shou Quan Fa Ming Zhuan Li Yi Xiang Lun Wen De Zhu Yao Nei Rong He Chuang Xin Dian You Yi 1.5 mmBo Duan Er:YbGong Xian Guang Xian Ji Guang Qi 1. Li Yong VBGZuo Wei Bo Chang Xuan Ze Yuan Jian ,Cai Yong Liang Duan Bu Tong Chang Du (7 m, 17 m)De Er:YbGong Xian Zeng Yi Guang Xian ,Fen Bie Shi Xian Liao Gong Zuo Bo Chang Tong Shi Fu Gai C band He L bandDe Kuan Diao Xie Ji Guang Shu Chu Gai Gong Zuo Fa Biao Zai Qi Kan IEEE Photonics Technology Letters 25(15) 1488 (2013)Shang 2. Shou Ci Jiang Shuang VBGGuang Pu Zhai Hua Ji Zhu Ying Yong Yu Er:YbGong Xian Guang Xian Ji Guang Qi Zhong ,Huo De Liao Zhong Xin Bo Chang Wei 1545.3 nm, Xian Kuan Xiao Yu ~38 pm, Gong Lu Wei 19.4 WDe Ji Guang Shu Chu Zai Jin Yi Bu De Shi Yan Zhong ,Jiang Shuang VBGYi Bing Lian Pai Lie De Fang Shi Ying Yong Dao Er:YbGong Xian Guang Xian Ji Guang Qi Zhong ,Shi Xian Liao Shuang Bo Chang Du Li De Lian Xu Ke Diao Xie Shu Chu ,Shuang Bo Chang Jian Ju Cong 0.3 nmDao 29.2 nm,Dang Bo Chang Jian Ju Wei 0.3 nmShi ,Huo De Liao Zui Da Gong Lu 17.9 WShu Chu ,Xie Xiao Lu Da 28.6% Liang Xiang Gong Zuo Fen Bie Fa Zai Zai Qi Kan IEEE Journal of Quantum Electronics 50(2) 88 (2014) Applied Physics Express 7(3) 032702 (2014)Shang 3. Jie He Guang Xian Ji Guang Qi You Liang De San Re Neng Li Yu Ti Kuai Zeng Yi Jie Zhi Neng Liang Cun Chu Rong Liang Da De You Dian ,Shou Ci Jiang Kuan Diao Xie Er:YbGong Xian Guang Xian Ji Guang Zuo Wei Tm:YAGTao Ci Ji Guang Qi Beng Pu Yuan ,Huo De Liao Zhong Xin Bo Chang Wei 2013.2 nm, Zui Da Gong Lu Wei 3.9 WDe Ji Guang Shu Chu Gai Gong Zuo Fa Biao Zai Qi Kan Applied Physics Express 6(3) 092107 (2013)Shang Er 1.6 mmBo Duan La Man Guang Xian Ji Guang Qi 1. Dui Yu Jian Bian Zhe She Lu Duo Mo Guang Xian De La Man Guang Xian Ji Guang Qi ,Zai Beng Pu Guang Xian Xing Xi Shou Jin Si Tiao Jian Xia ,Li Yong Lang Bo Han Shu (Lambert function)Tui Dao Chu Liao Miao Shu Duo Mo Guang Xian Zhong Shou Ji La Man San She (SRS)Guo Cheng De Bo Dong Fang Cheng De Jie Xi Jie ,Bing Jiang Qi Ying Yong Dao Shi Ji De La Man Guang Xian Ji Guang Qi She Ji He Can Shu You Hua Zhong ,Qu De Liao Jiao Hao De Xiao Guo 2. Jiang Bo Chang Suo Ding De 1545 nm Er:YbGong Xian Guang Xian Ji Guang Qi Zuo Wei Beng Pu Yuan ,Zai Ji Yu Pu Tong Jian Bian Zhe She Lu Duo Mo Tong Xin Guang Xian He Te Shu She Ji De Shuang Bao Ceng La Man Guang Xian De La Man Guang Xian Ji Guang Qi Zhong Fen Bie Shi Xian Liao Jin Yan She Ji Xian De 1.658 mm StokesJi Guang Shu Chu Chan Shu Liao Jian Bian Zhe She Lu Duo Mo Guang Xian Zhong SRSDe Guang Shu Ji Jing Zuo Yong ,Fen Xi Liao Jie Yue Xing Zhe She Lu Duo Mo Guang Xian Zhong Bu Cun Zai Gai Guang Shu Jing Hua Zuo Yong De Yuan Yin 3. Zai Ji Yu Jian Bian Zhe She Lu Guang Xian De La Man Guang Xian Ji Guang Qi Zhong ,Zi You Yun Zhuan Zhuang Tai Xia Huo De Liao Zui Gao Gong Lu Wei 12.3 WDe Ji Guang Shu Chu ,Li Yong VBGBo Chang Suo Ding Hou ,Shu Chu Ji Guang Xian Kuan Jin Wei ~0.1 nm,Zhe Shi Mu Qian Suo Bao Dao De Wa Liang Ji La Man Guang Xian Ji Guang Qi Zhong Suo Huo De De Zui Zhai Xian Kuan ;Bo Chang Diao Xie Yun Zhuan Shi Huo De Liao Cong 1638.5 nmDao 1675.1 nmGong 37 nmDe Diao Xie Fan Wei ,Zhe Ye Shi La Man Guang Xian Ji Guang Qi Xiang Dang Gong Lu Shu Chu Xia Zui Kuan De Bo Chang Diao Xie Fan Wei Geng Kuan De Bo Chang Diao Xie Fan Wei Ke Wang Tong Guo Gai Bian Beng Pu Yuan De Gong Zuo Bo Chang Shi Xian Gai Gong Zuo Fa Biao Zai Qi Kan Optics Express 22(6) 6605 (2014)Shang ,Qie Gai Ke Diao Xie La Man Guang Xian Ji Guang Qi Yi Huo Fa Ming Zhuan Li Shou Quan (Shou Quan Hao :CN 102761048) 4. Dui Bao Ceng Beng Pu De La Man Guang Xian Ji Guang Qi Jin Xing Liao Chu Bu De Shi Yan Tan Suo Yan Jiu Chan Shu Liao Shuang Bao Ceng La Man Guang Xian Can Shu She Ji De Ji Ben Zhun Ze He Shuang Bao Ceng La Man Guang Xian Zhong De SRSHe Mo Shi Ji Fa Guo Cheng ,Bing Zui Zhong Zhi Cheng Shuang Bao Ceng La Man Guang Xian Zai Zi You Yun Zhuan He VBGBo Chang Suo Ding De Bao Ceng Beng Pu La Man Guang Xian Ji Guang Qi Zhong Fen Bie Shi Xian Liao Gong Lu Wei 13.2 W, 10.4 W De 1.658 mm StokesJi Guang Shu Chu Dui Bao Ceng Beng Pu La Man Guang Xian Ji Guang Qi De Jin Yi Bu Gong Lu Ding Biao Fang Da Gei Chu Liao Fen Xi He Tao Lun", "author_names": [ "" ], "corpus_id": 126307833, "doc_id": "126307833", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Zhai Xian Kuan Er:YbGong Xian Guang Xian Ji Guang Beng Pu 1.6 mmBo Duan La Man Guang Xian Ji Guang Qi Yan Jiu", "venue": "", "year": 2014 }, { "abstract": "This editorial contains an overview of the contents of the current issue of the Photonics Letters of Poland, devoted mainly to optical metrology. A series of 14 papers deals with both technology as well as pure and applied physics. The scientific topic of the Photonic Letters of Poland, vol. 6(4)/2014 pertains measurements and characterization of photonic structures and systems as well as optical waveguides and nanolayers. The common denominator of all articles qualified for publication is widely understood, highly specialized optical metrology. The current issue of PLP presents investigations carried out in selected Polish scientific and research centers. The group from the Institute of Electron Technology in Warsaw has presented very recent results of investigations into quantum cascade lasers highly technologically advanced systems. A paper of the group from West Pomeranian University of Technology in Szczecin is devoted to analyses and investigations of quantum wells structures The authors from the Department of Optoelectronics at the Silesian University of Technology (SUT) in Gliwice present in several papers analyses, studies and researches concerning integrated optics structures including: interference, multimode interference, structures and systems of differential interferometry. The group from this Department also shows researches of topography and morphology of graphene and graphene oxide with respect to their application in optical and electrical sensors. The current issue contains also the work, in which the results of investigations are presented into optical fibers in terms of their application in optical telecommunications carried out by the Group from the Faculty of Electronics at the Wroclaw University of Technology. Birefringence measurements of polymer photonic crystal fibers infiltrated with liquid crystals by using the effect of light depolarization are presented by the authors from the Faculty of Physics at the Warsaw University of Technology. E mail: Tadeusz.Pustelny@polsl.pl In the paper entitled \"A low temperature operated NO2 gas POF sensor based on conducting graft polymer\" from the Department of Optoelectronics at SUT in Gliwice novel results are presented of investigations concerning a high sensitive gas sensor based on a polymer optical fiber. Polymer optical fibers are also the topic of the paper elaborated by a group of the Optical Fiber Technology Laboratory at the University of Lublin. The Group has examined the impact of electromagnetic radiation of high energy on mechanical and optical properties of polymeric materials for their application in the production of optical fibers. A group from the Gdansk University of Technology has presented the possibility of using polarization sensitive optical coherence tomography in the inspection of ceramic materials. A group from the Department of Metrology and Optoelectronics at the Poznan University of Technology presents a new approach to objective evaluation of human visual acuity. Another group from the Faculty of Physics at the Warsaw University of Technology shows the results of their studies on the influence of pitch and birefringence on solitons propagation at the disclination lines in a wedgeshaped planarly oriented sample of the chiral nematic liquid crystal. A very interesting subject concerning the application of a multi camera 3D Digital Image Correlation (DIC) system with the procedure of spatial data stitching is presented by the group from the Faculty of Mechatronics at the Warsaw University of Technology. The system diversifies single DIC setup capabilities used for displacement and strain measurements of big and complex structures such as industrial installations. It should be recognized that the papers contained in the volume 6(4)/2014 are interesting, and the investigations presented in the articles will be continued. Highly Specialized Optical Metrology", "author_names": [ "Tadeusz Pustelny" ], "corpus_id": 116631336, "doc_id": "116631336", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Highly Specialized Optical Metrology", "venue": "", "year": 2014 }, { "abstract": "http:/dx.doi.org/10.1016/j.patrec.2014.06.004 0167 8655/ 2014 Published by Elsevier B.V. This Special Edition in Celebration of Maria Petrou, was conceived shortly after she died in October 2012 and was in response to friends and colleagues who wanted to remember both her personal warmth and exceptional scientific achievements. The idea was to have a variety of contributions including novel scientific articles, reviews of topics close to Maria's areas of interest, and personal recollections from friends and colleagues. The call for papers was issued in May 2013 and resulted in 27 submissions. Of these about 8 were of a non technical nature and have been edited together to form the 'Homage to Maria Petrou' which is a compendium of recollections of various interactions with Maria, spanning her whole career. The remaining articles were of a technical nature, and have been peer reviewed according to the usual process followed in Pattern Recognition Letters. This peer review has produced 9 revised papers, which are also included in the Special Edition. These papers are authored by former students, colleagues and followers of Maria's work. All cite her contributions to the field and place themselves in the context of her work. Several of the articles list Maria as a posthumous co author. The technical contributions as follows: The paper 'Progress in the restoration of image sequences are degraded by atmospheric turbulence' by Ronen Gal, Nahum Kiryati and Nir Sochen reflects Maria's long standing interest in remote sensing, and explains how atmospheric degradation can be overcome in motion sequences. This interest in remote sensing was one of her earliest in the field of image analysis, and grew out of her first post in the area as a postdoc in the Department of Geography at Reading University. This lead her to work extensively on the problem of mixed pixels, and this interest is reflected in the paper 'Subpixel temporal spectral imaging' authored by former student Olga Duran and posthumously by Maria herself. Finally under the heading of remote sensing, a second posthumous paper 'A rule based classification methodology to handle uncertainty in habitat mapping employing evidential reasoning and fuzzy logic' authored by Zisis Petrou et al. describes how her work in AI and pattern recognition can be brought to bear on image interpretation problems in remote sensing. Maria always described herself as having a soft spot for geometry, and ascribed this to sharing her nationality with Pythagoras. The paper 'Rotation invariant co occurrence features based on digital circles and discrete Fourier transform' by Antonio Fernandez and Francesco Bianconi builds on this interest together with her long standing fascination with the Hough transform to present a new shape characterisation technique. Maria enjoyed teaching and preparing innovative teaching material. She also thought a great deal about how people learn and how you should best help them to learn. Many of her ideas here influenced the development of the tower of knowledge which is described in 'Tower of Knowledge for Scene Interpretation: A Survey' by Mai Xu and Zulin Wang. After first moving to Surrey, Maria developed an interest in the renormalisation group approach to image processing. This was a natural direction for her not only since the method draws on ideas from physics, but also that the original work in this area was performed by fellow Greek, Basilis Gidas. In the paper 'Fast pose invariant face recognition using super coupled multiresolution Markov Random Fields on a GPU' by Shervin Rahimzadeh Arashloo and Josef Kittler, the renormalisation group approach is applied to face recognition and efficiently implemented on a GPU. In her first post in computer vision at Reading University, Maria worked on an Alvey project with David Hogg, and was fascinated by his then pioneering work on modelling walking people. The paper 'Identification of people walking along curved trajectories' by Yumi Iwashita, Koichi Ogawara and Ryo Kurazume, captures this long standing interest, as does the paper 'Human Activity Recognition From 3D Data: A Review' by Lu Xia and Jake Aggarwal, which shows how far this field has moved over the past 25 years. As a physicist by training, Maria was instinctively drawn to problems involving light, and this influenced her recent work on photometric stereo. The papers 'Error analysis of photometric stereo with colour lights' by Martin Klaudiny and Adrian Hilton and 'Cast Shadows estimation and synthesis using the Walsh Transform' by Vasileios Argyriou, Ferdinand Redelinghuys and Maria herself, both address this research interest, with new insights into photometric stereo and how it can be employed in the real world. In addition to the scientific papers and the compendium of recollections, this special edition also contains accounts of her work at the University of Surrey and CERTH in Thessaloniki, together with a reprint of her obituary which appeared in the Guardian. We thank the authors of the technical papers and the personal recollections for providing us with the material for this celebration of Maria's life. We also thank Gabriella Sanniti di Baja for encouraging us to embark on editing it, and for her patience when the project ran slowly. We are also very grateful to the staff at Elsevier, especially Journal Manager Janet Amali Joseph who helped us bring the special edition into being. This is of course just one of several tributes to Maria. There will be a workshop in the Autumn of 2014 at CERTH to celebrate her scientific achievements. The IAPR, of which Maria served as both Newsletter Editor and Treasurer, among other posts, plans to remember Maria through a named biennial award to a female scientist. At the time of going to press, details of the award are still being discussed, but should be finalised in time for approval at the IAPR Governing Board Meeting in Stockholm, and an announcement during ICPR.", "author_names": [ "Edwin R Hancock", "Josef Kittler" ], "corpus_id": 45223232, "doc_id": "45223232", "n_citations": 3, "n_key_citations": 0, "score": 2, "title": "Celebrating the life and work of Maria Petrou", "venue": "Pattern Recognit. Lett.", "year": 2014 }, { "abstract": "El objetivo de esta tesis es contribuir al desarrollo de circuitos complejos en chips fotonicos de silicio. Para ello, se centra en dos retos principales: Por un lado, trata de elucidar la dinamica temporal de los efectos no lineales en silicio, especialmente la interaccion de los portadores libres con los pulsos opticos en el dominio del tiempo. Por otro lado, la tesis pretende contribuir a la miniaturizacion de los circuitos fotonicos mediante la integracion de guias fotonicas con guias plasmonicas.Entre los resultados mas destacables de esta tesis se encuentra la observacion, por primera vez, de compresion de pulsos de picosegundos mediante el efecto soliton (Nature Communications 5, 3160, 2014) Hasta la fecha no habia sido posible esta demostracion debido a la fuerte presencia de absorcion de dos fotones y portadores libres en longitudes de onda de comunicaciones. Este hito ha sido posible gracias al uso de una guia cristal fotonico con luz lenta y su dispersion especialmente disenada. En esta misma linea de investigacion se ha logrado tambien el descubrimiento de nuevos efectos no lineales en el dominio del tiempo relacionados con la presencia de los portadores libres en la guia. Incluso mas importante es la propuesta de usar la dispersion de la guia como mecanismo de control para los efectos generados por los portadores libres, resolviendo el problema mas grave de la optica no lineal en silicio.Otro resultado destacable es la demostracion numerica de acoplamiento eficiente entre guias de cristal fotonico y lineas de transmision plasmonicas en el infrarrojo medio, que presenta gran potencial en la miniaturizacion de circuitos en esta region del espectro (Applied Physics Letters 104, 011105 2014).Esperamos que los resultados presentados en esta tesis conlleven un avance en fotonica de silicio, posibilitando mayor funcionalidad y miniaturizacion de circuitos fotonicos en una plataforma compatible con las capacidades de fabricacion de silicio.", "author_names": [ "Andrea Blanco Redondo" ], "corpus_id": 127553625, "doc_id": "127553625", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Linear and nonlinear devices in silicon photonic waveguides", "venue": "", "year": 2014 }, { "abstract": "We report on the experimental observation of coherent phonon boundary scattering in micro scale phononic crystals (PnCs) at room temperature. We show that the neglecting coherent boundary scattering leads to gross overestimation of the measured thermal conductivities of the PnC samples. We introduce a hybrid model that accounts for partial coherent and partial incoherent phonon boundary scattering. Excellent agreement with the experiment is achieved. Almost all physical processes produce heat as a byproduct making thermoelectric (TE) systems very attractive for energy scavenging applications. Energy conversion in TE devices is based on the so called Peltier effect 1 Here the temperature gradient resulting from expelled heat is used to force electronic transport resulting in an electric current. As such, heat transported via phonons represents a leakage mechanism and serves to reduce the efficiency of TE systems. Indeed the inability to suppress or eliminate the relative phonon contribution to thermal transport as compared to the electronic one has hindered the development of efficient TE devices. Recently, it has been proposed that coherent boundary scattering in micro scale phononic crystals (PnCs) may hold the key to solving this problem by scattering phonons with minimal influence on electrons 2 4 PnCs are artificial structures with a periodic variation in mechanical impedance brought about by the introduction of holes or plugs of one material into a homogenous matrix of another 5 8 This periodic variation results in rich phonon dispersion with unusual behaviors 9 In this communication, we focus on micro scale PnCs formed by the introduction of air holes in a Si matrix with minimum feature sizes 100nm. As a phonon population traverses such a lattice, it can undergo two types of scattering processes: simple incoherent scattering as a result of encountering a boundary; and coherent Bragg like 7 scattering due to the periodic topology of the artificial lattice of air holes. In the first type, it is assumed that the phonons will retain no phase information after each scattering event. This implies that the phonon dispersion remains unaltered due to the introduction of the air holes. In the second type, on the other hand, it is assumed that the phase is preserved throughout several scattering events thus enabling coherent interference to occur. Consequently, this would imply a modified phonon dispersion that is sensitive to the topology of the PnC air hole lattice. Practically, this can have profound implications because: while incoherent boundary scattering depends only on the shape, size, and separation of the holes; coherent boundary scattering additionally depends on the symmetry and topology by which these holes are distributed. Thus, the existence of coherent scattering would allow one to further reduce the thermal conductivity of the underlying material without the need for additional boundaries (e.g. more air holes) by simply altering the PnC topology. The claim of coherent phonon scattering in micro scale Si/Air PnCs at room temperature has generated widespread controversy in the literature given the relatively small wavelength characteristic of the phonon population dominating the thermal transport 3,10 14 Experimentally however, the thermal conductivity (k) of PnC samples have consistently been measured to be significantly lower than that of an unpatterned film 2,4,11,13,14 In fact far lower than what would be expected due to the combination of material removal and simple incoherent boundary scattering 2,4,13 thereby suggesting that another k reduction mechanism, possibly coherent scattering, must be taking place. The The 2nd Intenational Conference on Phononics and Thermal Energy Science (PTES2014) Shanghai, China, May 26 May 31, 2014 controversy was heightened by the discovery that ~50% of k in Si is carried by phonons with mean free paths (MFPs) from 100nm up to 1mm15, which was recently verified experimentally 16 Since it is logical to assume that a phonon remains coherent over its MFP, we suggest here that the MFP, rather than wavelength, should be used when judging whether or not coherent scattering events can take place. In which case, a large enough fraction of the phonon population could travel sufficient distances to experience the PnC lattice periodicity and thus undergo coherent scattering. We report on the experimental observation of coherent phonon boundary scattering in micro scale phononic crystals (PnCs) at room temperature. We investigate the existence of coherent phonon boundary scattering resulting from the periodic topology of the PnCs and its influence on the thermal in silicon. To delaminate incoherent from coherent boundary scattering, PnCs with a fixed minimum feature size, differing only in the unit cell topologies, were fabricated. A suspended island platform was used to measure the thermal conductivity. We show that the neglecting coherent boundary scattering leads to gross overestimation of the measured thermal conductivities of the PnC samples. We introduce a hybrid model that accounts for partial coherent and partial incoherent phonon boundary scattering. Excellent agreement with the experiment is achieved emphasizing the influence of coherent zone folding in PnCs. Our results yield conclusive evidence that significant room temperature coherent phonon boundary scattering does indeed take place. References 1 Slack, G. A. CRC Handbook of Thermoelectrics. (CRC Press, 1995) Hopkins, P. E. et al. Reduction in the Thermal Conductivity of Single Crystalline Silicon by Phononic Crystal Patterning. Nano Lett 11, 107 112, doi:Doi 10.1021/Nl102918q (2011) 3 Reinke, C. M. et al. Thermal conductivity prediction of nanoscale phononic crystal slabs using a hybrid lattice dynamics continuum mechanics technique. AIP Advances 1, 041403 041414 (2011) 4 Yu, J. K. Mitrovic, S. Tham, D. Varghese, J. Heath, J. R. Reduction of thermal conductivity in phononic nanomesh structures. Nature Nanotechnology, 5, 718 721, (2010) 5 Reinke, C. M. Su, M. F. Olsson, R. H. El Kady, I. Realization of optimal bandgaps in solid solid, solid air, and hybrid solid air solid phononic crystal slabs. Appl Phys Lett 98, doi:Artn 061912 Doi 10.1063/1.3543848 (2011) 6 Su, M. F. Olsson, R. H. Leseman, Z. C. El Kady, I. Realization of a phononic crystal operating at gigahertz frequencies. Appl Phys Lett 96, 053111 (053113 pp. doi:10.1063/1.3280376 (2010) 7 Olsson, R. H. III et al. in IEEE International Ultrasonics Symposium. 1150 1153. 8 El Kady, I. Olsson, R. H. III Fleming, J. G. Phononic band gap crystals for radio frequency communications. Appl Phys Lett 92, 233504 233501 233503, doi:10.1063/1.2938863 (2008) 9 Kushwaha, M. S. Halevi, P. Dobrzynski, L. Djafari Rouhani, B. Acoustic band structure of periodic elastic composites. Physical Review Letters 71, 2022 2025 (1993) 10 Hao, Q. Chen, G. Jeng, M. S. Frequency dependent Monte Carlo simulations of phonon transport in two dimensional porous silicon with aligned pores. Journal of Applied Physics 106, 114321 114310 (2009) 11 Tang, J. et al. Holey Silicon as an Efficient Thermoelectric Material. Nano Lett 10, 4279 4283, doi:10.1021/nl102931z (2010) 12 Jain, A. Yu, Y. J. McGaughey, A. J. H. Phonon transport in periodic silicon nanoporous films with feature sizes greater than 100 nm. Physical Review B 87, 195301 (2013) 13 Bongsang, K. et al. in Micro Electro Mechanical Systems (MEMS) 2012 IEEE 25th International Conference on 176 179 (2012) 14 El Kady, I. et al. Phonon Manipulation with Phononic Crystals. (Sandia National Laboratories, 2012) 15 Esfarjani, K. Chen, G. Stokes, H. T. Heat transport in silicon from first principles calculations. Physical Review B 84, 085204 (2011)", "author_names": [ "Ihab El-Kady", "Charles M Reinke", "Seyedhamidreza Alaie", "Drew F Goettler", "Mehmet F Su", "Zayd C Leseman" ], "corpus_id": 123791915, "doc_id": "123791915", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Thermal Transport in Micro Scale Phononic Crystals: Observation of Coherent Phonon Scattering at Room Temperature.", "venue": "", "year": 2014 }, { "abstract": "El principal objetivo de esta Tesis Doctoral es el estudio analitico y numerico de dispositivos multipuerta, MuG del ingles Multiple Gate, y compuestos semiconductores III V, como alternativas tecnologicas para continuar el proceso de escalado del transistor MOSFET mas alla del nodo tecnologico de 22nm [delAlamo2011] Con este objetivo, se han implementado simuladores electrostaticos y de transporte capaces de resolver las ecuaciones de Schrodinger, Poisson y Boltzmann en un gas de electrones unidimensional. El simulador electrostatico esta basado en la aproximacion de masa efectiva no parabolica [Jin2007] siendo capaz de tratar con geometrias, materiales y orientaciones arbitrarias para obtener las distribuciones de carga y potencial en la seccion transversal bidimensional de la estructura MuG [Marin2012] El simulador de transporte linealiza la ecuacion de transporte unidimensional de Boltzmann, usando la aproximacion de tiempo de relajacion del momento, MRT del ingles Momentum Relaxation Time, [Esseni2011] resolviendo el sistema resultante de manera implicta. Ademas incluye modelos novedosos de dispersion debida a rugosidad superficial [Stanojevic2013,Jin2013] cargas coulombianas [Ning1972,Gamiz1994,Gamiz2002] fonones bulk [Kotlyar2004,Jin2007, Ashcroft1976,Tienda2012] fonones opticos polares [OReagan2010,Wang1993,Leburton1992] y desorden por aleacion [Bastard1988,Pham2007] Adicionalmente, se ha desarrollado un modelo completamente analitico que describe el comportamiento electrostatico de nanohilos [Marin2012b] NW del ingles nanowire. Es, hasta donde alcanza nuestro conocimiento, la descripcion analitica mas completa de la distribucion de la carga y el potencial en NWs cilindricos fabricados con materiales III V presentada en la literatura hasta la fecha. El modelo proporciona expresiones analiticas para calcular la energia de las subbandas y las funciones de onda del valle Gamma, teniendo en cuenta la penetracion de la funcion de onda en el aislante y la discontinuidad en la masa efectiva en la interfaz entre el aislante y el semiconductor, asi como estadistica de Fermi Dirac, confinamiento bidimensional de los portadores y la no parabolicidad de la banda de conduccion. Tambien permite incluir un perfil arbitrario de estados en la interfaz. Haciendo uso de las aproximaciones numerica y analitica, se realizan varios estudios relevantes de caracter electrostatico y del transporte en Trigates y NWs. Estas dos estructuras son especialmente siginificativas puesto que constituyen las arquitecturas MuG mas consolidadas. Los Trigate introducen pocos cambios respecto al proceso de fabricacion planar tradicional, al mismo tiempo que incrementan el control electrosatico del canal [Radosavljevic2010,Colinge2004] Los NWs son la evolucion ultima de las arquitecturas MuG, proporcionando la mayor supresion de los efectos de canal corto [delAlamo2011] De esta manera, usando el enfoque analitico se estudia la influencia del tamano del dispositivo y el tipo de material en la carga en inversion, la corriente de drenador, la capacidad de puerta y la tension umbral en nanohilos III V [Marin2013,Marin2014] Para completar el estudio analitico, los simuladores numericos desarrollados se han utilizado para comprender el papel del valle L en las propiedades electrostaticas y de transporte, concluyendo que tiene un influencia no despreciable a medida que el tamano del dispositivo se reduce. El enfoque numerico se usa tambien para comparar el comportamiento de estructuras Trigate de Si y materiales III V. El impacto de la anchura del Trigate y de la puerta trasera es analizada, mostrando que: a) el incremento de la movilidad observado para Trigates III V se degrada cuando la anchura se reduce y b) el control de la puerta trasera sobre la tension umbral afecta directamente a la movilidad [Ruiz2013,Ruiz2013] Finalmente, la rugosidad superficial se revela como el principal mecanismo de dispersion limitador de la movilidad para la gran mayoria de tamanos y materiales a alto campo, siendo su comportamiento a bajo campo mas complicado y muy dependiente del tamano y material empleados. Referencias [Ashcroft1976] N.W. Ashcroft and N.D. Mermin. Solid state physics. Saunders College, 1976. [Bastard1988] G. Bastard. Wave mechanics applied to semiconductor heterostructures. Monographies de physique. Les Editions de Physique, 1988. [Colinge2004] J. P. Colinge. Multiple gate SOI MOSFETs. Solid State Electronics, 48:897,Jun 2004. [delAlamo2011] J.A. del Alamo. Nanometre scale electronics with III V compound semiconductors. Nature, 479:317, Nov 2011. [Esseni2011] D. Esseni, P. Palestri, and L. Selmi. Nanoscale MOS Transistors: Semi classical Transport And Applications. Cambridge University Press, New York. USA, 2011. [Gamiz1994] F. Gamiz, J. A. Lopez Villanueva, J. A. Jimenez Tejada, I. Melchor, and A. Palma. A comprehensive model for coulomb scattering in inversion layers. Journal of Applied Physics, 75:924, 1994. [Gamiz2002] F. Gamiz, F. Jimenez Molinos, J. B. Roldan, and P. Cartujo Cassinello. Coulomb scattering model for ultrathin silicon on insulator inversion layers. Applied Physics Letters, 80:3835, 2002. [Jin2007] S. Jin, M. V. Fischetti, and T. Tang. Modeling of electron mobility in gated silicon nanowires at room temperature: Surface roughness scattering, dielectric screening, and band nonparabolicity. Journal of Applied Physics, 102:083715, Oct 2006. [Jin2013] S. Jin, S. M. Hong, W. Choi, K. H. Lee, and Y. Park. Coupled drift diffusion (DD) and multi subband boltzmann transport equation (MSBTE) solver for 3D multi gate transistors. In Simulation of Semiconductor Processes and Devices (SISPAD) 2013 International Conference on, page 348, Sept 2013. [Kotlyar2004] R. Kotlyar, B. Obradovic, P. Matagne, M. Stettler, and M. D. Giles. Assessment of room temperature phonon limited mobility in gated silicon nanowires. Applied Physics Letters, 84:5270, 2004. [Leburton1992] J. P. Leburton. Optic phonon limited transport and anomalous carrier cooling in quantum wire structures. Physical Review B, 45:11022, 1992. [Marin2012] E. G. Marin, F. G. Ruiz, A. Godoy, I. M. Tienda Luna, and F. G amiz. Effect of interfacial states on the technological variability of Trigate MOSFETs. In Silicon Nanoelectronics Workshop (SNW) 2012 IEEE, 2012. [Marin2012] E. G. Marin, F. G. Ruiz, I. M. Tienda Luna, A. Godoy, P. Sanchez Moreno, and F. Gamiz. Analytic potential and charge model for III V Surrounding Gate MOSFETs. Journal of Applied Physics, 112:084512, Oct 2012. [Marin2013] E.G. Marin, F.J.G. Ruiz, I.M. Tienda Luna, A. Godoy, and F. Gamiz. Analytical gate capacitance modeling of III V nanowire transistors. IEEE Transactions on Electron Devices, 60(5):1590, May 2013. [Marin2014] E.G. Marin, F.G. Ruiz, I.M. Tienda Luna, A. Godoy, and F. Gamiz. Analytical model for the threshold voltage of III V nanowire transistors including quantum effects. Solid State Electronics, 92:28, Feb 2014. [Ning1972] T. H. Ning and C. T. Sah. Theory of scattering of electrons in a nondegenerate semiconductor surface inversion layer by surface oxide charges. Physical Review B, 6:4605, 1972. [OReagan2010] T. P. OReagan, M. V. Fischetti, B. Soree, S. Jin, W. Magnus, and M. Meuris. Calculation of the electron mobility in III V inversion layers with high dielectrics. Journal of Applied Physics, 108:103705, 2010. [Pham2007] A. T. Pham, C. Jungemann, and B. Meinerzhagen. Physics based modeling of hole inversion layer mobility in strained SiGe on insulator. IEEE Transactions on Electron Devices, 54:2174, 2007. [Radosavljevic2010] M. Radosavljevic, G. Dewey, J. M. Fastenau, J. Kavalieros, R. Kotlyar, B. Chu Kung, et al. Non planar, multi gate InGaAs quantum well field effect transistors with high k gate dielectric and ultra scaled gate to drain/gate to source separation for low power logic applications. In Electron Devices Meeting (IEDM) 2010 IEEE International, page 126, Dec 2010. [Ruiz2013] F. G. Ruiz, E. G. Marin, I. M. Tienda Luna, A. Godoy, C.Martinez Blanque, and F. Gamiz. Influence of the back gate bias on the electron mobility of a trigate MOSFETs. In Simulation of Semiconductor Processes and Devices (SISPAD) 2013 International Conference on, page 304, 2013. [Ruiz2012] F. G. Ruiz, E. G. Marin, I. M. Tienda Luna, A. Godoy, C.Martinez Blanque, and F. G ?miz. Back gate biasing influence on the electron mobility and the a threshold voltage of ultra thin box Multigate MOSFET. In Silicon Nanoelectronics Workshop (SNW) 2013 IEEE, 2012. [Stanojevic2013] Z. Stanojevic and H. Kosina. Surface roughness scattering in non planar channels: The role of band anisotropy. In Simulation of Semiconductor Processes and Devices (SISPAD) 2013 International Conference on, page 352, Sept 2013. [Tienda210] I. M. Tienda Luna, F. G. Ruiz, A. Godoy, E. G. Marin. and F. G amiz. Dependence of the phonon limited mobility in arbitrarily oriented si nanowires. In Computational Electronics (IWCE) 2010 15th International Workshop on, 2012. [Wang1993] T. Wang and T.W. Chen T. H. Hsieh. Quantum confinement effects on low dimensional electron mobility. Journal of Applied Physics, 74:426, 1993.", "author_names": [ "Nestor Ricardo Gonzalez Marin" ], "corpus_id": 125801873, "doc_id": "125801873", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Modeling and simulation of semiconductor nanowires for future technology nodes", "venue": "", "year": 2014 }, { "abstract": "In recent years, gallium phosphide based nanostructures, particularly indium gallium arsenide quantum dots (QD) embedded in gallium phosphide, have attracted interest of a growing number of research groups worldwide. InxGa1 xAs/GaP QDs are a possible solution for two current issues of the semiconductor industry: Monolithic integration of photonic devices based on III V semiconductors with silicon based electronics, and realization of a fast and non volatile electronic memory. The present thesis lays the groundwork for technological applications of InxGa1 xAs/ GaP QDs. The fabrication of InxGa1 xAs/GaP QDs by metalorganic vapour phase epitaxy and control of their structural properties like size and areal density via parameters of the epitaxial process are being developed. The structure of the QDs can be linked directly to their optical and electronic properties. Thus, the QDs can be tailored to fit a specific application. The electronic structure of InxGa1 xAs/GaP heterostructures generally is indirect in reciprocal and/or direct space due to high material strain. For the first time, the present work demonstrates a way to reduce this material strain and to fabricate InxGa1 xAs/GaP QDs with high efficient optical recombination channels, which is crucial for photonic devices. Besides technological applications, InxGa1 xAs/GaP QDs thereby present an ideal system to study fundamental interaction processes of QDs with surrounding material in dependence upon their electronic structure. First detailed analysis of the electronic structure of InxGa1 xAs/GaP QDs by means of optical and capacitance spectroscopy is presented. The theoretically predicted electronic structure of InxGa1 xAs/GaP QDs at the threshold between indirect and direct optical recombinations is confirmed. An evaluation of the technological potential of InxGa1 xAs/GaP QDs for electronic memories yields a storage time at room temperature three orders of magnitude larger compared to InxGa1 xAs/GaAs QDs. A non volatile memory can be realized by systematic further development of the GaP based material system. Teile dieser Arbeit wurden bereits veroffentlicht: G. Stracke, E. M. Sala, S. Selve, T. Niermann, A. Schliwa, A. Strittmatter und D. Bimberg, Indirect and direct optical transitions in In0.5Ga0.5As/GaP quantum dots Applied Physics Letters 104 (12) 123107 (2014) C. Prohl, A. Lenz, D. Roy, J. Schuppang, G. Stracke, A. Strittmatter, U. W. Pohl, D. Bimberg, H. Eisele und M. Dahne, Spatial structure of In0.25Ga0.75As/GaAs/GaP quantum dots on the atomic scale, Applied Physics Letters 102 (12) 123102 (2013) G. Stracke, A. Glacki, T. Nowozin, L. Bonato, S. Rodt, C. Prohl, A. Lenz, H. Eisele, A. Schliwa, A. Strittmatter, U. W. Pohl und D. Bimberg, Growth of In0.25Ga0.75As quantum dots on GaP utilizing a GaAs interlayer Applied Physics Letters 101 (22) 223110 (2012)", "author_names": [ "Gernot Stracke" ], "corpus_id": 183399118, "doc_id": "183399118", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Wachstum und Charakterisierung von InGaAs Quantenpunkten auf GaP Substraten", "venue": "", "year": 2014 } ]
n type organic semiconductor
[ { "abstract": "During the past decade, it has been shown that light matter strong coupling of materials can lead to modified and often improved properties which has stimulated considerable interest. While charge transport can be enhanced in n type organic semiconductors by coupling the electronic transition and thereby splitting the conduction band into polaritonic states, it is not clear whether the same process can also influence carrier transport in the valence band of p type semiconductors. Here we demonstrate that it is indeed possible to enhance both the conductivity and photoconductivity of a p type semiconductor rr P3HT that is ultrastrongly coupled to plasmonic modes. It is due to the hybrid light matter character of the virtual polaritonic excitations affecting the linear response of the material. Furthermore, in addition to being enhanced, the photoconductivity of rr P3HT shows a modified spectral response due to the formation of the hybrid polaritonic states. This illustrates the potential of engineering the vacuum electromagnetic environment to improve the optoelectronic properties of organic materials.", "author_names": [ "Kalaivanan Nagarajan", "Jino George", "Anoop Thomas", "Eloise Devaux", "Thibault Chervy", "S Azzini", "Kripa Joseph", "Abdelaziz Jouaiti", "Mir Wais Hosseini", "Anilesh Kumar", "Cyriaque Genet", "Nicola Bartolo", "Cristiano Ciuti", "Thomas W Ebbesen" ], "corpus_id": 221163496, "doc_id": "221163496", "n_citations": 15, "n_key_citations": 0, "score": 2, "title": "Conductivity and Photoconductivity of a p Type Organic Semiconductor under Ultrastrong Coupling.", "venue": "ACS nano", "year": 2020 }, { "abstract": "Abstract A p type organic thin film transistor (OTFT) was fabricated based on an axially substituted phthalocyanine (titanium phthalocyanine dichloride: TiCl2Pc) Molecular energies and atomic charge distributions of a series of axially substituted metal phthalocyanines were studied using measurements of their electrochemical properties and X ray photoemission spectroscopy, respectively. Based on these measurements, the relationship between the charge carrier transport types of the phthalocyanines in OTFTs and their substituted groups (metal and axial ligands) are discussed. The axially substituted electron withdrawing groups can effectively lower the LUMO energy and increase the charge separation, contributing to the realization of n type behavior, e.g. in SnCl2Pc. The electronegativity of the metal also affects the LUMO energies and charge distributions, such that TiCl2Pc is a p type semiconductor.", "author_names": [ "Chang Wook Song", "Ye Li", "Chen Gao", "Hao Zhang", "Ya-hui Chuai", "De Song" ], "corpus_id": 216213658, "doc_id": "216213658", "n_citations": 3, "n_key_citations": 0, "score": 1, "title": "An OTFT based on titanium phthalocyanine dichloride: A new p type organic semiconductor", "venue": "", "year": 2020 }, { "abstract": "A novel photoactive semiconductor (named as IDTOT 4F) with an A p D p A type configuration is synthesized. It contains an electron donating fused ring (D) as the core flanked with two p spacers and is end capped with two electron withdrawing units (A) The intramolecular charge transfer effect endows IDTOT 4F with strong and broad light absorption and a relatively narrow band gap (1.46 eV) Thin film optoelectrical devices based on IDTOT 4F exhibit both n type and p type switching behaviors. Besides, the p channel device shows significantly photoresponsive performance with the maximum P (photo/dark current ratio) R (photoresponsivity) and D* (detectivity) values of around 60, 0.07 AW 1, and 2.5 x 1010 Jones, respectively. Further, IDTOT 4F based optoelectrical devices exhibit good optical memory characteristics with a time constant t 1 of 4.6 h, indicating its applicability to nonvolatile optical memory devices. The results provide new insights into the photoresponsive behavior of fused ring semiconductors and pave the way for the design of nonvolatile optical memory devices.", "author_names": [ "Shiyu Feng", "Donghuan Dai", "Yao Lin", "Shuonan Chen", "Xiaosong Wu", "Weiguo Huang" ], "corpus_id": 221804992, "doc_id": "221804992", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "An A p D p A Type Organic Semiconductor Based Optoelectrical Device With Photo Response and Optical Memory Behaviors", "venue": "Frontiers in Materials", "year": 2020 }, { "abstract": "We have investigated the characteristics of bottom gate and top contact type field effect transistors fabricated with polycrystalline thin films of a liquid crystalline organic semiconductor, 2 decyl 7 phenyl benzothienobenzothiophene (Ph BTBT 10) with a p type dopant, tetrafluoro tetracyano quinodimethane (F4 TCNQ) We found that the contact resistance between the semiconductor and electrode was reduced from 3.0 kO cm to 1.2 kO cm by contact doping with F4 TCNQ, and to 0.9 kOcm by subsequent thermal annealing of the films, in which the F4 TCNQ dopant diffused from the surface to the interior of the Ph BTBT 10 thin film. In addition, we found that contact doped and thermally annealed devices showed higher mobility and smaller threshold voltage in short channel devices compared to pristine devices. We conclude that thermal diffusion of dopants to improve FET performance is an important technique.", "author_names": [ "Shun Takamaru", "Jun-ichi Hanna", "Hiroaki Iino" ], "corpus_id": 233815177, "doc_id": "233815177", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Use of doping to achieve low contact resistance in bottom gate top contact type organic transistor with liquid crystalline organic semiconductor, Ph BTBT 10", "venue": "", "year": 2021 }, { "abstract": "Bias stress instability has been a challenging problem and a roadblock for developing stable p type organic field effect transistors (OFETs) This device instability is hypothesized as due to electron correlated charge carrier trapping, neutralization and recombination at semiconductor/dielectric interfaces and in semiconductor channels. Here in this paper a strategy is demonstrated to improve the bias stress stability by constructing multi layered drain electrode with energy level modification layers (ELMLs) Several organic small molecules with high LUMO energy levels are experimented as ELMLs. The energy level offset between the Fermi level of the drain electrode and the LUMOs of the ELMLs are shown to construct interfacial barrier, which suppresses electron injection from the drain electrode into the channel leading to significantly improved bias stress stability of OFETs. The mechanism of the ELMLs on the bias stress stability is studied by quantitative modeling analysis of charge carrier dynamics. Of all injection models evaluated, it is found that Fowler Nordheim tunneling describes best the observed experimental data. Both theory and experimental data show that, by using the ELMLs with higher LUMO levels, the electron injection can be suppressed effectively and the bias stress stability of p type OFETs can thereby be improved significantly.", "author_names": [ "Zhenxin Yang", "Chunhua Guo", "Changsheng Shi", "Deng-Ke Wang", "Tao Zhang", "Qiang Zhu", "Zhenghong Lu" ], "corpus_id": 221347995, "doc_id": "221347995", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Improving Bias Stress Stability of p Type Organic Field Effect Transistors by Constructing Electron Injection Barrier at the Drain Electrode/Semiconductor Interfaces.", "venue": "ACS applied materials interfaces", "year": 2020 }, { "abstract": "Photosynthetic biohybrid systems have emerged as a promising platform for solar to chemical conversion by integrating excellent light harvesting ability of semiconductors with the synthetic capability of biological cells. How to enhance the utilization of solar energy, hole/electron separation efficiency and the electron transfer between the semiconductor and biological cells is crucial to develop high performance photosynthesis platforms. In this work, we developed an organic semiconductor bacteria biohybrid photosynthetic system, which could efficiently realize CO 2 reduction to produce acetic acid through non photosynthetic bacteria Moorella thermoacetica As the photosensitizers, both cationic electron transporting n type) perylene diimide derivative (PDI) and hole transporting p type) poly(fluorene co phenylene) (PFP) were coated on the bacteria surface to form p n heterojunction (PFP/PDI) layer, affording higher hole/electron separation efficiency. The p conjugated semiconductors possess excellent light harvesting ability and biocompatibility, and more importantly, the cationic side chains of organic semiconductors could intercalate into cell membrane, ensuring the efficient electron transfer to bacteria. As a result, Moorella thermoacetica can harvest photoexcited electrons from the PFP/PDI heterojunction, which can drive the Wood Ljungdahl pathway to synthesize acetic acid from CO 2 under illumination. The efficiency of this organic biohybrid is 1.6% which is comparable to those of reported inorganic biohybrid systems. This work opens a new avenue to explore bioenergy application of organic semiconductors, and also provides a convenient biomanufacturing approach to design organic semiconductor bacteria biohybrids for efficient solar to chemical conversion.", "author_names": [ "Panpan Gai", "Ruilian Qi", "Libing Liu", "Fengting Lv", "Shu Wang" ], "corpus_id": 211136633, "doc_id": "211136633", "n_citations": 19, "n_key_citations": 0, "score": 0, "title": "Solar Powered Organic Semiconductor Bacteria Biohybrids for CO2 Reduction into Acetic Acid.", "venue": "Angewandte Chemie", "year": 2020 }, { "abstract": "We report the synthesis of 1,4 dicarbonyl compounds and substituted alkenes (Mizoroki Heck type coupling) starting from secondary and tertiary alkyl halides and vinyl acetate or styrene derivatives using visible light photocatalysis. The protocol uses mesoporous graphitic carbon nitride (mpg CN) as a heterogeneous organic semiconductor photocatalyst and Ni(II) salts as Lewis acid catalysts. Detailed post characterization of the heterogeneous material has been carried out to support the proposed catalytic cycle. Apart from high functional group tolerance, mild reaction conditions, scalability as well as easy recovery and reuse of the mpg CN photocatalyst provide a practical solution to these widespread transformations in terms of sustainability and efficiency and this methodology is recommended for applications in academic and industrial synthesis.", "author_names": [ "Jagadish Khamrai", "Saikat Das", "Aleksandr Savateev", "Markus Antonietti", "Burkhard Konig" ], "corpus_id": 233834834, "doc_id": "233834834", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Mizoroki Heck type reactions and synthesis of 1,4 dicarbonyl compounds by heterogeneous organic semiconductor photocatalysis", "venue": "", "year": 2021 }, { "abstract": "Organic semiconductors (OSCs) materials are currently under intense investigation because of their potential applications such as organic field effect transistors, organic photovoltaic devices, and organic light emitting diodes. Inspired by the selenization strategy can promote anisotropic charge carrier migration, and selenium containing compounds have been proved to be promising materials as OSCs both for hole and electron transfer. Herein, we now explore the anisotropic transport properties of the series of selenium containing compounds. For the compound containing SeSe bond, the SeSe bond will break when attaching an electron, thus those compounds cannot act as n type OSCs. About the different isomer compounds with conjugated structure, the charge transfer will be affected by the stacking of the conjugated structures. The analysis of chemical structure and charge transfer property indicates that Se containing materials are promising high performance OSCs and might be used as p type, n type, or ambipolar OSCs. Furthermore, the symmetry of the selenium containing OSCs will affect the type of OSCs. In addition, there is no direct relationship between the R groups with their performance, whether it or not as p type OSCs or n types. This work demonstrates the relationship between the optoelectronic function and structure of selenium containing OSCs materials and hence paves the way to design and improve optoelectronic function of OSCs materials.", "author_names": [ "Daoyuan Zheng", "Yurong Guo", "Mingxing Zhang", "Xia Feng", "Lina Zhu", "Lijuan Qiu", "Xiaoning Jin", "Guangjiu Zhao" ], "corpus_id": 210149642, "doc_id": "210149642", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Anisotropic charge carrier transport of optoelectronic functional selenium containing organic semiconductor materials", "venue": "J. Comput. Chem.", "year": 2020 }, { "abstract": "A kind of continuous flexible paper substrate thin film transistors (TFTs) of the ratio of a controllable length to width nickel (Ni) two dimensionally connected metal organic frameworks, Ni TCNQ (TCNQ 7, 7, 8, 8 tetracyanoquinodimethane) has been prepared skillfully by using all ink jet printing Ni(NO3)2*6H2O and the TCNQ hydrothermal interface in situ reaction method. The structure analysis of Ni TCNQ on copper electrodes was revealed by combining transmission electron microscope and powder x ray diffraction techniques, indicating that it has a lamellar and porous structure. The morphology and structure of the transistor channel are stacked up by nanosheets of 2D lattice of [Ni(C12H4N4)2]n, which is further verified by scanning electron microscope, FT IR, and x ray photoelectron spectroscopy. I V characteristics show that electrical behaviors of the p type junctionless TFT are fabricated at room temperature.", "author_names": [ "Zhi-Pei Jiang", "Caihong Li", "Hezhuang Liu", "Jihua Zou", "Zhaoquan Xu", "Jiang Wu", "Zhiming M Wang" ], "corpus_id": 225330900, "doc_id": "225330900", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Signature of p type semiconductor features in paper based back gate metal organic framework thin film transistors", "venue": "", "year": 2020 }, { "abstract": "Abstract The isolation of graphene on an insulating substrate has provided new opportunities for the fabrication of electronic devices with radically new geometries and structures. The use of single layer graphene as an electrode has enabled the development of novel electronic device architectures that exploit the unique atomically thin structure of the material, which also includes a low density of states at its charge neutrality point. In this work, we present the first example of a vertical Schottky junction photodiode based on the graphene organic semiconductor metal heterostructure. The n type N,N' dioctyl 3,4,9,10 perylenedicarboximide (PTCDI C8) organic semiconductor was thermally deposited onto chemical vapor deposition (CVD) grown single layer graphene. The tunable Schottky injection barrier permitted tuning of the diode rectification ratio by more than two orders of magnitude upon application of gate biases, which increased the photocurrent but suppressed the dark current of the photodiodes. Tuning of the photovoltaic properties of the devices was also confirmed, indicating that the device architecture based on the work function tunability of graphene could provide a versatile strategy for enhancing the performance of organic photodiodes.", "author_names": [ "Young-jin Choi", "Hwi Je Woo", "Seongchan Kim", "Jia Sun", "Moon-Sung Kang", "Young Jae Song", "Jeong Ho Cho" ], "corpus_id": 219920622, "doc_id": "219920622", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Schottky junction photodiode based on graphene organic semiconductor heterostructure", "venue": "", "year": 2020 } ]
Perovskite light-emitting diode, Low starting voltage
[ { "abstract": "Hybrid perovskite semiconductors represent a promising platform for color tunable light emitting diodes (LEDs) and lasers; however, the behavior of these materials under the intense electrical excitation required for electrically pumped lasing remains unexplored. Here, we investigate methylammonium lead iodide based perovskite LEDs under short pulsed drive at current densities up to 620 A cm 2. At low current density (J 10 A cm 2) we find that the external quantum efficiency (EQE) depends strongly on the time averaged history of the pulse train and show that this curiosity is associated with slow ion movement that changes the internal field distribution and trap density in the device. The impact of ions is less pronounced in the high current density regime (J 10 A cm 2) where EQE roll off is dominated by a combination of Joule heating and charge imbalance yet shows no evidence of Auger loss, suggesting that operation at kA cm 2 current densities relevant for a laser diode should be within reach.Hybrid perovskite semiconductors are promising for wavelength tunable laser diodes but their behavior under intense electrical excitation remains unexplored. Kim et al. investigate perovskite light emitting diodes at current densities nearing 1 kA cm 2 and suggest that a laser diode is within reach.", "author_names": [ "Hoyeon Kim", "Lianfeng Zhao", "Jared Scott Price", "Alex J Grede", "Kwang Chul Roh", "Alyssa N Brigeman", "Mike Lopez", "Barry P Rand", "Noel C Giebink" ], "corpus_id": 53713589, "doc_id": "53713589", "n_citations": 72, "n_key_citations": 2, "score": 1, "title": "Hybrid perovskite light emitting diodes under intense electrical excitation", "venue": "Nature Communications", "year": 2018 }, { "abstract": "Lead halide perovskite quantum dots (LHP QDs) exhibit great potential in the backlighting display of light emitting diode applications. Light emitting backlighting with high brightness, low cost, a.", "author_names": [ "Xicheng Wang", "Zhen Bao", "Yu-Chun Chang", "Ru-Shi Liu" ], "corpus_id": 225116686, "doc_id": "225116686", "n_citations": 17, "n_key_citations": 0, "score": 1, "title": "Perovskite Quantum Dots for Application in High Color Gamut Backlighting Display of Light Emitting Diodes", "venue": "", "year": 2020 }, { "abstract": "This is the first report of an investigation on flexible perovskite solar cells for artificial light harvesting by using a white light emitting diode (LED) lamp as a light source at 200 and 400 lx, values typically found in indoor environments. Flexible cells were developed using either low temperature sol gel or atomic layer deposited compact layers over conducting polyethylene terephthalate (PET) substrates, together with ultraviolet (UV) irradiated nanoparticle TiO2 scaffolds, a CH3NH3PbI3 xClx perovskite semiconductor, and a spiro MeOTAD hole transport layer. By guaranteeing high quality carrier blocking (via the 10 40 nm thick compact layer) and injection (via the nanocrystalline scaffold and perovskite layers) behavior, maximum power conversion efficiencies (PCE) and power densities of 10.8% and 7.2 mW*cm 2, respectively, at 200 lx, and 12.1% and 16.0 mW*cm 2, respectively, at 400 lx were achieved. These values are the state of the art, comparable to and even exceeding those of flexible dye sensitized solar cells under LED lighting, and significantly greater than those for flexible amorphous silicon, which are currently the main flexible photovoltaic technologies commercially considered for indoor applications. Furthermore, there are significant margins of improvement for reaching the best levels of efficiency for rigid glass based counterparts, which we found was a high of PCE ~24% at 400 lx. With respect to rigid devices, flexibility brings the advantages of being low cost, lightweight, very thin, and conformal, which is especially important for seamless integration in indoor environments.", "author_names": [ "Giulia Lucarelli", "Francesco Di Giacomo", "Valerio Zardetto", "Mariadriana Creatore", "Thomas M Brown" ], "corpus_id": 136230737, "doc_id": "136230737", "n_citations": 58, "n_key_citations": 2, "score": 1, "title": "Efficient light harvesting from flexible perovskite solar cells under indoor white light emitting diode illumination", "venue": "Nano Research", "year": 2017 }, { "abstract": "In this study, a dual source vapor evaporation method was employed to fabricate the high quality CsPbBr3 thin films with a good crystalline and high surface coverage. Temperature dependent and excitation power dependent photoluminescence measurements were performed to study the optical properties of the CsPbBr3 material. Further, based on the experimental data, the temperature sensitivity coefficient of band gap and exciton binding energy were estimated. More importantly, for the first time, we designed and prepared a hole injection layer free perovskite light emitting diode (LED) based on the Au/MgO/CsPbBr3/n MgZnO/n+ GaN structure, producing an intense green emission ~538 nm) with a high purity. Besides, the device demonstrated a high luminance of 5025 cd/m2, an external quantum efficiency of 1.46% a current efficiency of 1.92 cd/A, and a power efficiency of 1.76 lm/W. We studied in detail the current voltage and electroluminescence properties of the prepared device and proposed the hole generation models and the carrier transport/recombination mechanisms to make these interesting characteristics certain. The results obtained would provide a new and effective strategy for the design and preparation of perovskite LEDs.", "author_names": [ "Zhifeng Shi", "Lingzhi Lei", "Yunfeng Li", "Fei Zhang", "Zhuang-zhuang Ma", "Xinjian Li", "Di Wu", "Tingting Xu", "Yongtao Tian", "Bao-lin Zhang", "Zhiqiang Yao", "Guotong Du" ], "corpus_id": 206486491, "doc_id": "206486491", "n_citations": 18, "n_key_citations": 0, "score": 0, "title": "Hole Injection Layer Free Perovskite Light Emitting Diodes.", "venue": "ACS applied materials interfaces", "year": 2018 }, { "abstract": "All inorganic perovskite light emitting diode (PeLED) has a high stability in ambient atmosphere, but it is a big challenge to achieve high performance of the device. Basically, device design, control of energy level alignment, and reducing the energy barrier between adjacent layers in the architecture of PeLED are important factors to achieve high efficiency. In this study, we report a CsPbBr3 based PeLED with an inverted architecture using lithium doped TiO2 nanoparticles as the electron transport layer (ETL) The optimal lithium doping balances the charge carrier injection between the hole transport layer and ETL, leading to superior device performance. The device exhibits a current efficiency of 3 cd A 1, a luminance efficiency of 2210 cd m 2, and a low turn on voltage of 2.3 V. The turn on voltage is one of the lowest values among reported CsPbBr3 based PeLEDs. A 7 fold increase in device efficiencies has been obtained for lithium doped TiO2 compared to that for undoped TiO2 based devices.", "author_names": [ "Alagesan Subramanian", "Zhenghui Pan", "Zhenbo Zhang", "Imtiaz Ahmad", "Jing Chen", "Meinan Liu", "Shuang Cheng", "Yijun Xu", "Jingjing Wu", "Wei Lei", "Qasim Khan", "Yuegang Zhang" ], "corpus_id": 4643323, "doc_id": "4643323", "n_citations": 28, "n_key_citations": 0, "score": 0, "title": "Interfacial Energy Level Alignment for High Performance All Inorganic Perovskite CsPbBr3 Quantum Dot Based Inverted Light Emitting Diodes.", "venue": "ACS applied materials interfaces", "year": 2018 }, { "abstract": "Abstract The traditional hot injection (HI) process needs high temperature, inert gas protection, and localized injection operation, which severely hinder their large scale industrialization. Moreover, the CsPb1 xSnxBr3 HI QDs exhibit poor stability. Herein, we report the room temperature (RT) synthesis of CsPb1 xSnxBr3 perovskite QDs by modified ligand assisted reprecipitation (LARP) approach. Compared with the CsPb1 xSnxBr3 HI QDs reported in literatures, the CsPb1 xSnxBr3 RT QDs show higher photoluminescence quantum yield (PLQY) and better stability: the CsPb0.9Sn0.1Br3 RT QDs obtain the highest PLQY of more than 91% and the stability of the film made with this QDs still maintain more than 80% of its original fluorescence strength after 120 days in air environment. Because of the superior PLQY, light emitting diodes (LEDs) based on the RT QDs is constructed, and it exhibits an external quantum efficiency (EQE) of 1.8% a luminance of 1600 cdm 2, a current efficiency of 4.89 cdA 1, a power efficiency of 6.41 lmw 1, and a low on voltage of 3.6 V. The present work provides a feasible method for large scale industrial synthesis of perovskite QDs at room temperature and shows that the CsPb1 xSnxBr3 RT QDs are promising for highly efficient LEDs.", "author_names": [ "Jidong Deng", "Haoran Wang", "Jiao Xun", "Jingxi Wang", "Xuyong Yang", "Wei Shen", "Ming Li", "Rongxing He" ], "corpus_id": 210517327, "doc_id": "210517327", "n_citations": 11, "n_key_citations": 0, "score": 1, "title": "Room temperature synthesis of excellent performance CsPb1 Sn Br3 perovskite quantum dots and application in light emitting diodes", "venue": "", "year": 2020 }, { "abstract": "Halide perovskite multiple quantum wells (MQWs) have recently shown great potential in the field of light emitting diodes. We report a facile solution based approach to fabricate dimensionality tunable perovskite MQWs by introducing 1 naphthylmethylammonium (NMA) cations into CsPbI3 perovskites. Through the dimensional tailoring of (NMA)2Csn 1PbnI3n+1 perovskite MQWs, the crystallinity and photoluminescence quantum efficiencies (PLQEs) are significantly improved. We have obtained high performance red perovskite light emitting diodes (PeLEDs) with a luminance of 732 cd m 2 and a maximum external quantum efficiency of 7.3% which are among the best performing red PeLEDs. Significantly, the maximum luminance of our PeLEDs is obtained at a low applied voltage of 3.4 V, with a turn on voltage close to the perovskite band gap (Vturn on 1.9 V) These outstanding performance characteristics demonstrate that dimensional tailoring of perovskite MQWs is a feasible and effective strategy to achieve high performance PeLEDs, which is attractive for full color display applications of perovskites.", "author_names": [ "Jin Chang", "Shuting Zhang", "Nana Wang", "Yan Sun", "Yingqiang Wei", "Renzhi Li", "Chang Yi", "Jianpu Wang", "Wei Huang" ], "corpus_id": 3776081, "doc_id": "3776081", "n_citations": 61, "n_key_citations": 1, "score": 1, "title": "Enhanced Performance of Red Perovskite Light Emitting Diodes through the Dimensional Tailoring of Perovskite Multiple Quantum Wells.", "venue": "The journal of physical chemistry letters", "year": 2018 }, { "abstract": "Organometal halide perovskites (OHPs) have become the most promising optoelectronic material in the past few years with a myriad of applications in the photovoltaic, light emitting, and laser fields. However, for light emitting applications, the low photoluminescence quantum yield (PLQY) of OHP film is critical to hinder the efficiency improvement of OHP film based light emitting diodes (PeLEDs) Herein, we study the effects of rubidium incorporation on the crystal growth, structure, and photoelectric and optical properties of formamidinium lead bromide based (FAPbBr3 based) perovskite films and light emission performance of PeLEDs. It is found that rubidium incorporation can significantly enhance the PLQY of FAPbBr3 film by suppressing the trap density and thus improve the withstand voltage as well as the performance of PeLEDs. When FAPbBr3 film with optimal Rb doping ratio is employed as the light emitter of PeLEDs, the maximum luminance and current efficiency is enhanced by ~10 fold and ~5 fold to 66 353 cd/m2 and 24.22 cd/A compared to the controlled device, respectively, the record performance based on FAPbBr3 PeLEDs so far. The enhanced performance can be chiefly attributed to the increase of PLQY and decrease of trap defect density of perovskite film with rubidium incorporation. Our research is expected to stimulate the development of OHPs for the next generation lighting and display fields.", "author_names": [ "Yifei Shi", "Jun Xi", "Ting Lei", "Fang Yuan", "Jinfei Dai", "Chenxin Ran", "Hua Dong", "Bo Jiao", "Xun Hou", "Zhaoxin Wu" ], "corpus_id": 206480880, "doc_id": "206480880", "n_citations": 40, "n_key_citations": 0, "score": 1, "title": "Rubidium Doping for Enhanced Performance of Highly Efficient Formamidinium Based Perovskite Light Emitting Diodes.", "venue": "ACS applied materials interfaces", "year": 2018 }, { "abstract": "Perovskite light emitting diode (PeLED) has been vigorously developed in recent years. As it has demonstrated well performance on the rigid substrates, the next important direction of PeLED is their integration with stretchable components to realize stretchable, responsive device. Here, we describe a facile fabrication of stretchable perovskite light emissive touch responsive devices (PeLETDs) through utilizing highly transparent and conductive polyurethane/silver nanowires (PU/AgNWs) as the electrode. Meanwhile, a stretchable tri composite perovskite emissive layer was developed by blending a small amount of poly(ethylene oxide) (PEO) and polyvinylpyrrolidone (PVP) with CsPbBr3. Additionally, a thin PVP layer was introduced at the bottom side of the emissive layer. On one hand, it can further improve the morphology of the emissive layer; on the other hand, it can serve as an electron injection barrier to reduce the high non radiative recombination at the corresponding interface. Further, to fulfill the responsive function of the fabricated PeLEDs, a poly(ethylene terephthalate) (PET) spacer with a 100 mm thickness was inserted between the top electrode and the emissive layer. A stretchable PeLETD is finally demonstrated to possess a low turn on voltage of 2 V with a brightness of 380.5 cd m 2 at 7.5 V, and can sustain 30% uniaxial strain with a small luminance variation of 24% More intriguingly, our stretchable PeLETD exhibited high stability, which could be well touch responsibility, where the luminance is on/off switched for 300 cycles by the repeated pressure.", "author_names": [ "Dai-Hua Jiang", "Yi-Chun Liao", "Chia-Jung Cho", "Loganathan Veeramuthu", "Fang-Cheng Liang", "Ting-Chieh Wang", "Chu-Chen Chueh", "Toshifumi Satoh", "Shih-Huang Tung" ], "corpus_id": 211726036, "doc_id": "211726036", "n_citations": 13, "n_key_citations": 1, "score": 1, "title": "Facile Fabrication of Stretchable Touch Responsive Perovskite Light Emitting Diodes through Using Robust Stretchable Composite Electrodes.", "venue": "ACS applied materials interfaces", "year": 2020 }, { "abstract": "Although all inorganic perovskite light emitting diodes (PeLED) have satisfactory stability under an ambient atmosphere, producing devices with high performance is challenging. A device architecture with a reduced energy barrier between adjacent layers and optimized energy level alignment in the PeLED is critical to achieve high electroluminescence efficiency. In this study, we report the optimization of a CsPbBr3 based PeLED device structure with Li doped TiO2 nanoparticles as the electron transport layer (ETL) Optimal Li doping balances charge carrier injection between the hole transport layer (HTL) and ETL, leading to superior performance in both devices. The turn on voltages for devices with Li doped TiO2 nanoparticles were significantly reduced from 7.7 V to 4.9 V and from 3 V to 2 V in the direct and inverted PeLED structures, respectively. The low turn on voltage for green emission is one of the lowest values among the reported CsPbBr3 based PeLEDs. Further investigations show that the device with an inverted structure is superior to the device with a direct structure because the energy barrier for carrier injection was minimized. The inverted structure devices exhibited a current efficiency of 5.6 cd A 1 for the pristine TiO2 ETL, while it was 15.2 cd A 1 for the Li doped TiO2 ETL, a factor of ~2.7 enhancement at 5000 cd m 2.", "author_names": [ "Qasim Khan", "Alagesan Subramanian", "Guannan Yu", "Khan Maaz", "Delong Li", "Rizwan Ur Rehman Sagar", "Keqiang Chen", "Wei Lei", "Babar Shabbir", "Yupeng Zhang" ], "corpus_id": 73470179, "doc_id": "73470179", "n_citations": 25, "n_key_citations": 0, "score": 1, "title": "Structure optimization of perovskite quantum dot light emitting diodes.", "venue": "Nanoscale", "year": 2019 } ]
machine learning and parallel computing
[ { "abstract": "Tremendous progress has been witnessed in artificial intelligence within the domain of neural network backed deep learning systems and its applications. As we approach the post Moore's Law era, the limit of semiconductor fabrication technology along with a rapid increase in data generation rates have lead to an impending growing challenge of tackling newer and more modern machine learning problems. In parallel, quantum computing has exhibited rapid development in recent years. Due to the potential of a quantum speedup, quantum based learning applications have become an area of significant interest, in hopes that we can leverage quantum systems to solve classical problems. In this work, we propose a quantum deep learning architecture; we demonstrate our quantum neural network architecture on tasks ranging from binary and multi class classification to generative modelling. Powered by a modified quantum differentiation function along with a hybrid quantum classic design, our architecture encodes the data with a reduced number of qubits and generates a quantum circuit, loading it onto a quantum platform where the model learns the optimal states iteratively. We conduct intensive experiments on both the local computing environment and IBM Q quantum platform. The evaluation results demonstrate that our architecture is able to outperform Tensorflow Quantum by up to 12.51% and 11.71% for a comparable classic deep neural network on the task of classification trained with the same network settings. Furthermore, our GAN architecture runs the discriminator and the generator purely on quantum hardware and utilizes the swap test on qubits to calculate the values of loss functions. In comparing our quantum GAN, we note our architecture is able to achieve similar performance with 98.5% reduction on the parameter set when compared to classical GANs. With the same number of parameters, additionally, QuGAN outperforms other quantum based GANs in the literature for up to 125.0% in terms of similarity between generated distributions and original data sets. Keywords Quantum Machine Learning; Quantum Deep Learning; Quantum Generative Adversarial Networks; Quantum State Fidelity Preprints (www.preprints.org) NOT PEER REVIEWED Posted: 24 March 2021 doi:10.20944/preprints202103.0583.v1", "author_names": [ "Samuel A Stein" ], "corpus_id": 233638067, "doc_id": "233638067", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Quantum Computing Aided Machine Learning Through Quantum State Fidelity", "venue": "", "year": 2021 }, { "abstract": "As the training dataset size and the model size of machine learning increase rapidly, more computing resources are consumed to speedup the training process. However, the scalability and performance reproducibility of parallel machine learning training, which mainly uses stochastic optimization algorithms, are limited. In this paper, we demonstrate that the sample difference in the dataset plays a prominent role in the scalability of parallel machine learning algorithms. We propose to use statistical properties of dataset to measure sample differences. These properties include the variance of sample features, sample sparsity, sample diversity, and similarity in sampling sequences. We choose four types of parallel training algorithms as our research objects: (1) the asynchronous parallel SGD algorithm (Hogwild! algorithm) (2) the parallel model average SGD algorithm (minibatch SGD algorithm) (3) the decentralization optimization algorithm, and (4) the dual coordinate optimization (DADM algorithm) Our results show that the statistical properties of training datasets determine the scalability upper bound of these parallel training algorithms.", "author_names": [ "Daning Cheng", "Shigang Li", "Hanping Zhang", "Fen Xia", "Yunquan Zhang" ], "corpus_id": 232043263, "doc_id": "232043263", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Why Dataset Properties Bound the Scalability of Parallel Machine Learning Training Algorithms", "venue": "IEEE Transactions on Parallel and Distributed Systems", "year": 2021 }, { "abstract": "This special issue of Concurrency and Computation: Practice and Experience comprises four papers extending the original workshop publications accepted and presented at MPP 2019 (8th Workshop on Parallel Programming Models Special Issue on IoT and Machine Learning) held in Rio de Janeiro in conjunction with IPDPS 2019. The papers represent interesting research ideas of parallel programming models, tools, and optimizations suited for being applied to IoT based applications. The paper titled \"Enabling Heterogeneous Ray Tracing Acceleration in Edge/Cloud Architectures\" represents a very interesting research on reconfigurable accelerators for Ray Tracing, specialized in computing ray triangle intersections at the network edge of a heterogeneous cloud computing environment. The authors validated their approach on the Xilinx Zynq FPGA platform. The paper titled \"An Incremental Reinforcement Learning Scheduling Strategy for Data Intensive Scientific Workflows in the Cloud\" is a research work proposing a new scheduling algorithm based on Reinforcement Learning for scientific workflows on HPC distributed resources and Clouds. The paper titled \"Latency aware Adaptive Micro Batching Techniques for Streamed Data Compression on GPUs\" proposes a set of Autonomic Computing strategies for configuring the optimal parallelism degree and batch size on streaming data compression parallel applications on GPU architectures. Finally, the paper titled \"Gamma General Abstract Model for Multiset mAnipulation and Dynamic Dataflow Model: an Equivalence Study\" is an interesting research study on new applications of the Gamma Model (General Abstract Model for Multiset mAnipulation) and its joint utilization with the Dataflow programming model. As Guest Editors, we would like to express our gratitude for the valuable contributions made by all authors. We would like to thank all the reviewers who helped us during the thorough review process based on several review rounds. Finally, we would like to thank all the editorial board members and all staff of Concurrency and Computation: Practice and Experience for allowing us to publish our Special Issue and for their invaluable support during the whole publication process.", "author_names": [ "Cristiana Barbosa Bentes", "Felipe Maia Galvao Franca", "Leandro Augusto Justen Marzulo", "Gabriele Mencagli", "Mauricio Lima Pilla" ], "corpus_id": 233964655, "doc_id": "233964655", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Novel parallel processing techniques for IoT based machine learning applications", "venue": "Concurr. Comput. Pract. Exp.", "year": 2021 }, { "abstract": "Forecasting the dynamics of large complex networks from previous time series data is important in a wide range of contexts. Here we present a machine learning scheme for this task using a parallel architecture that mimics the topology of the network of interest. We demonstrate the utility and scalability of our method implemented using reservoir computing on a chaotic network of oscillators. Two levels of prior knowledge are considered: (i) the network links are known; and (ii) the network links are unknown and inferred via a data driven approach to approximately optimize prediction.", "author_names": [ "Keshav Srinivasan", "Nolan J Coble", "Joyce L Hamlin", "Thomas M Antonsen", "Edward Ott", "Michelle Girvan" ], "corpus_id": 237346805, "doc_id": "237346805", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Parallel Machine Learning for Forecasting the Dynamics of Complex Networks", "venue": "ArXiv", "year": 2021 }, { "abstract": "We observe a continuously increased use of Deep Learning (DL) as a specific type of Machine Learning (ML) for data intensive problems (i.e. 'big data' that requires powerful computing resources with equally increasing performance. Consequently, innovative heterogeneous High Performance Computing (HPC) systems based on multi core CPUs and many core GPUs require an architectural design that addresses end user communities' requirements that take advantage of ML and DL. Still the workloads of end user communities of the simulation sciences (e.g. using numerical methods based on known physical laws) needs to be equally supported in those architectures. This paper offers insights into the Modular Supercomputer Architecture (MSA) developed in the Dynamic Exascale Entry Platform (DEEP) series of projects to address the requirements of both simulation sciences and data intensive sciences such as High Performance Data Analytics (HPDA) It shares insights into implementing the MSA in the Julich Supercomputing Centre (JSC) hosting Europe No. 1 Supercomputer Julich Wizard for European Leadership Science (JUWELS) We augment the technical findings with experience and lessons learned from two application communities case studies (i.e. remote sensing and health sciences) using the MSA with JUWELS and the DEEP systems in practice. Thus, the paper provides details into specific MSA design elements that enable significant performance improvements of ML and DL algorithms. While this paper focuses on MSA based HPC systems and application experience, we are not losing sight of advances in Cloud Computing (CC) and Quantum Computing (QC) relevant for ML and DL.", "author_names": [ "Morris Riedel", "Rocco Sedona", "Chadi Barakat", "Petur Einarsson", "Reza Hassanian", "Gabriele Cavallaro", "Matthias Book", "Helmut Neukirchen", "Andreas Lintermann" ], "corpus_id": 235639155, "doc_id": "235639155", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Practice and Experience in using Parallel and Scalable Machine Learning with Heterogenous Modular Supercomputing Architectures", "venue": "2021 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW)", "year": 2021 }, { "abstract": "Today's systems, especially in the age of federated learning, rely on sending all the data to the cloud, and then use complex algorithms, such as Deep Neural Networks, which require billions of parameters and many hours to train a model. In contrast, the human brain can do much of this learning effortlessly. Hyperdimensional (HD) Computing aims to mimic the behavior of the human brain by utilizing high dimensional representations. This leads to various desirable properties that other Machine Learning (ML) algorithms lack such as: robustness to noise in the system and simple, highly parallel operations. In this paper, we propose HyDREA, a HD computing system that is Robust, Efficient, and Accurate. To evaluate the feasibility of HyDREA in a federated learning environment with wireless communication noise, we utilize NS 3, a popular network simulator that models a real world environment with wireless communication noise. We found that HyDREA is 48x more robust to noise than other comparable ML algorithms. We additionally propose a Processing in Memory (PIM) architecture that adaptively changes the bitwidth of the model based on the signal to noise ratio (SNR) of the incoming sample to maintain the robustness of the HD model while achieving high accuracy and energy efficiency. Our results indicate that our proposed system loses less than 1% classification accuracy, even in scenarios with an SNR of 6.64. Our PIM architecture is also able to achieve 255x better energy efficiency and speed up execution time by 28x compared to the baseline PIM architecture.", "author_names": [ "Justin Morris", "Kazim Ergun", "Behnam Khaleghi", "Mohsen Imani", "Baris Aksanli", "Tajana Simunic" ], "corpus_id": 232054454, "doc_id": "232054454", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "HyDREA: Towards More Robust and Efficient Machine Learning Systems with Hyperdimensional Computing", "venue": "2021 Design, Automation Test in Europe Conference Exhibition (DATE)", "year": 2021 }, { "abstract": "Elastic scaling in/out of operator parallelism degree is needed for processing real time dynamic data streams under low latency and high stability requirements. Usually the operator parallelism degree is set when a streaming application is submitted to a stream computing system and kept intact during runtime. This may substantially affect the performance of the system due to the fluctuation of input streams and availability of system resources. To address the problems brought by the static parallelism setting, we propose and implement a machine learning based elastic strategy for operator parallelism (named MeStream) in big data stream computing systems. The architecture of Me Stream and its key models are introduced, including parallel bottleneck identification, parameter plan generation, parameter migration and conversion, and instances scheduling. Metrics of execution latency and process latency of the proposed scheduling strategy are evaluated on the widely used big data stream computing system Apache Storm. The experimental results demonstrate the efficiency and effectiveness of the proposed strategy.", "author_names": [ "Dawei Sun", "Rajkumar Buyya" ], "corpus_id": 237056513, "doc_id": "237056513", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "A Machine Learning based Elastic Strategy for Operator Parallelism in a Big Data Stream Computing System", "venue": "", "year": 2021 }, { "abstract": "We present a CMOS imager for low latency face detection empowered by parallel imaging and computing of machine learning (ML) classifiers. The energy efficient parallel operation and multi scale detection eliminate image capture delay and significantly alleviate backend computational loads. The proposed pixel architecture, composed of dynamic samplers in a global shutter (GS) pixel array, allows for energy efficient in memory charge domain computing of feature extraction and classification. The illumination invariant detection was realized by using log Haar features. A prototype 240x240 imager achieved an on chip face detection latency of 5.1ms with a 97.9% true positive rate and 2% false positive rate at 120fps. Moreover, a dynamic nature of in memory computing allows an energy efficiency of 419pJ/pixel for feature extraction and classification, leading to the smallest latency energy product of 3.66msnJ/pixel with digital backend processing.", "author_names": [ "Juan Salinas", "Euisik Yoon" ], "corpus_id": 236980967, "doc_id": "236980967", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A5.1ms Low Latency Face Detection Imager with In Memory Charge Domain Computing of Machine Learning Classifiers", "venue": "2021 Symposium on VLSI Technology", "year": 2021 }, { "abstract": "We present a CMOS imager for low latency face detection empowered by parallel imaging and computing of machine learning (ML) classifiers. The energy efficient parallel operation and multi scale detection eliminate image capture delay and significantly alleviate backend computational loads. The proposed pixel architecture, composed of dynamic samplers in a global shutter (GS) pixel array, allows for energy efficient in memory charge domain computing of feature extraction and classification. The illumination invariant detection was realized by using log Haar features. A prototype 240x240 imager achieved an on chip face detection latency of 5.1ms with a 97.9% true positive rate and 2% false positive rate at 120fps. Moreover, a dynamic nature of in memory computing allows an energy efficiency of 419pJ/pixel for feature extraction and classification, leading to the smallest latency energy product of 3.66msnJ/pixel with digital backend processing.", "author_names": [ "Hyunsoo Song", "Sungjin Oh", "Juan Salinas", "Euisik Yoon" ], "corpus_id": 236480416, "doc_id": "236480416", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A 5.1ms Low Latency Face Detection Imager with In Memory Charge Domain Computing of Machine Learning Classifiers", "venue": "2021 Symposium on VLSI Circuits", "year": 2021 }, { "abstract": "To detect defect is an important concept in machine leaning techniques and ambiguous dataset which develops into a challenging issue, as the software product expands in terms of size and its complexity. This chapter reveals an applied novel multi learner model which is ensembled to predict software metrics using classification algorithms and propose algorithm applied in parallel method for detection on ambiguous data using density sampling and develop an implementation running on both GPUs and multi core CPUs. The defect on the NASA PROMISE defect dataset is adequately predicted and classified using these models and implementing GPU computing. The performance compared to the traditional learning models improved algorithm and parallel implementation on GPUs shows less processing time in ensemble model compared to decision tree algorithm and effectively optimizes the true positive rate.", "author_names": [ "Sivakumar S", "Sreedevi E", "PremaLatha V", "Haritha D" ], "corpus_id": 228894848, "doc_id": "228894848", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Parallel Defect Detection Model on Uncertain Data for GPUs Computing by a Novel Ensemble Learning", "venue": "", "year": 2021 } ]
Bi2OS2
[ { "abstract": "Layered semiconductors with broad photoabsorption, a long carrier lifetime and high carrier mobility are of crucial importance for high performance optoelectronic and photovoltaic devices; however it is hard to satisfy these requirements simultaneously in a system due to the opposite dependence on the layer thickness. Herein, by means of ab initio time domain nonadiabatic molecular dynamic simulations, we find a new mechanism in Bi2OS2 nanosheets inducing an anomalous layer dependent property of carrier lifetimes, which makes the few layered Bi2OS2 a possible system for fulfilling the above requirements concurrently. It is revealed that the interlayer dipole dipole interaction in few layered Bi2OS2 effectively breaks the two fold degenerate orbitals of [BiS2] layers, which not only cuts down the overlap of the electron and hole wave functions, but also accelerates the electron decoherence process. This significantly suppresses the electron hole recombination and prolongs the photogenerated carrier lifetime of few layered Bi2OS2. The mechanism unveiled here paves a possible way for developing advanced optoelectronic and photovoltaic devices through engineering interlayer dipole dipole coupling.", "author_names": [ "Xianghong Niu", "Guangfen Wu", "Xiweng Zhang", "Jinlan Wang" ], "corpus_id": 212406558, "doc_id": "212406558", "n_citations": 5, "n_key_citations": 0, "score": 0, "title": "Interlayer coupling prolonged the photogenerated carrier lifetime of few layered Bi2OS2 semiconductors.", "venue": "Nanoscale", "year": 2020 }, { "abstract": "Although polymer solar cells (PSCs) have many advantages, they have obtained great progress in the two decades, the low charge carrier mobility still restricts performance progress of PSCs. Two dimensional (2D) Bi based semiconductor nanomaterial (Bi2OS2) can be a potential material for improving the charge carrier mobility in the active layer of PSCs, because it exhibits a high carrier mobility, suitable band gap, wide absorption range, and good stability. In this work, we synthesize the 2D Bi2OS2 nanomaterial and incorporate it into active layer of PSCs as a third component for the first time. By introduction 1 wt% 2D Bi2OS2 nanomaterial into the PSCs, the power conversion efficiency (PCE) of PSCs can be obviously improved by more than 17% comparison with binary PSCs (from 10.51% to 12.31% The enhancement of PCE is mainly due to the improving of charge transport, surface morphology, and crystallization of active layer. It is worth noting that the 2D Bi2OS2 play the role of the heterogeneous nucleation in the active layer, resulting in the enhanced crystallization of PBDB T and ITIC. These results not only provide a way to improve the performance of PSCs, but also show that the 2D Bi2OS2 nanomaterial has great potential application in the PSCs.", "author_names": [ "Chengwen Huang", "Huangzhong Yu" ], "corpus_id": 214143224, "doc_id": "214143224", "n_citations": 4, "n_key_citations": 0, "score": 1, "title": "Enhanced carrier mobility and power conversion efficiency of organic solar cells by adding 2D Bi2OS2", "venue": "", "year": 2020 }, { "abstract": "Correction for 'Interlayer coupling prolonged the photogenerated carrier lifetime of few layered Bi2OS2 semiconductors' by Xianghong Niu et al. Nanoscale, 2020, 12, 6057 6063, DOI: 10.1039/D0NR00447B.", "author_names": [ "Xianghong Niu", "Guangfen Wu", "Xiweng Zhang", "Jinlan Wang" ], "corpus_id": 220429882, "doc_id": "220429882", "n_citations": 4, "n_key_citations": 0, "score": 0, "title": "Correction: Interlayer coupling prolonged the photogenerated carrier lifetime of few layered Bi2OS2 semiconductors.", "venue": "Nanoscale", "year": 2020 }, { "abstract": "Abstract In this paper, three dimensional (3D) nanoripple like ZnO nanorod arrays (R ZnO NRAs) are successfully fabricated and modified by two dimensional (2D) Bi2OS2 material, and inverted polymer solar cells (IPSCs) with R ZnO modified by Bi2OS2 as electron transmission layer (ETL) are fabricated for the first time. The results show that the surface morphologies of R ZnO NRAs can be controlled by adjusting the concentration of the modified 2D Bi2OS2 solution. Bi2OS2 modification can not only suppress the surface defects of R ZnO NRAs, reduce the recombination of photogenerated charges, but also increase crystallinity of the active layer, resulting in effective electron collection. And thus, the performance of IPSCs is obviously improved. The power conversion efficiency (PCE) of PTB7: PCBM based PSCs with R ZnO NRAs modified by 2% Bi2O2S as ETL is considerably raised to 7.31% from 5.51% More interestingly, Bi2OS2 modification enhances IPSCs stability to remain 80.9% of their initial PCE after 80 days, yet IPSCs with pristine R ZnO NRAs remain only 47.4% of their initial PCE. Moreover, this approach can also successfully improve the performance of another IPSC composed of PBDB T: ITIC blends. The PCE of the device based on 2% Bi2OS2 modified R ZnO NRAs is improved to 9.94% from 8.03% of the reference device without Bi2OS2 modification. This work not only provides an effective mean of surface modification of R ZnO NRAs, but also shows the Bi2OS2 material has potential application in PSCs.", "author_names": [ "Zuping Wu", "Chengwen Huang", "Chunling Hou" ], "corpus_id": 213516025, "doc_id": "213516025", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Surface modification on nanoripple like ZnO nanorod arrays using two dimensional (2D) Bi2OS2 to fabricate high performance inverted polymer solar cells", "venue": "", "year": 2020 }, { "abstract": "Abstract Additive engineering has been proved to be an effective method to increase the performance of perovskite solar cells (PVSCs) by increasing the quality of the perovskite thin film. Two dimensional (2D) Bi2OS2 nanomaterial is an excellence optoelectronic material because of its tunable direct band gap, ultra high charge mobility, wide absorption range and high absorption coefficient. In this work, 2D Bi2OS2 nanosheets are synthesized and introduced as additives into the perovskite precursor solution to adjust the film formation process for the first time. Serving as heterogeneous nucleation site, 2D Bi2OS2 can reduce the nucleation barrier and assist the formation of highly crystalline and crystal orientation along the (1 1 0) plane perovskite thin film, which is beneficial to improve the mobility and lifetime of charge carriers. Besides, X ray photoelectron spectroscopy (XPS) measurement reveals that 2D Bi2OS2 nanosheets can interact with Pb2+ within the perovskite through Pb S bond, thus suppressing the uncoordinated Pb2+ ions trap states. Scanning electron microscope (SEM) demonstrates 2D Bi2OS2 nanosheets can fill up the pin holes and grain boundaries on the perovskite film surface. Ultraviolet photoelectron spectroscopy (UPS) measurement indicates that the valence band (VB) of optimized perovskite film is 0.28 eV upshifted closer to the highest occupied molecular orbital (HOMO) of the hole transport layer (HTL) which accelerates the charge transportation at perovskite/HTL interface. Consequently, the average power conversion efficiency (PCE) of 18.96% (highest PCE of 19.89% is achieved upon incorporating 2D Bi2OS2 nanosheets with an optimized concentration of 0.02 mg/ml into MAPbI3 precursor solution, which is greatly improved compared to the average PCE of 15.71% for the control devices (highest PCE of 16.77% Besides, the lifetime of optimized PVSCs is also prolonged due to the less defect states and better perovskite film quality. This work not only provides a facile method to increase the PCE and stability of PVSCs, but also reveals 2D Bi2OS2 material has potential applications in PVSCs.", "author_names": [ "Chen Jinyun", "Jiankai Zhang", "Chengwen Huang", "Zhuoneng Bi", "Huangzhong Yu", "Shengwei Shi", "Xueqing Xu" ], "corpus_id": 228929309, "doc_id": "228929309", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Two dimensional Bi2OS2 doping improves the performance and stability of perovskite solar cells", "venue": "", "year": 2020 }, { "abstract": "Two dimensional (2D) semiconductors with desirable band gaps and high carrier mobility are highly sought after for future application in nanoelectronics. Herein, by means of first principles calculations, we predict that a new 2D material, namely a Bi2OS2 nanosheet, possesses not only a tunable direct band gap, but also ultra high electron mobility (up to 26 570 cm2 V 1 s 1) More interestingly, an anomalous layer dependent band gap is revealed, derived from the synergetic effect of the quantum confinement and intrinsic surface electron states. 2D Bi2OS2 also exhibits excellent absorption over the entire solar spectrum and the absorption coefficient is comparable to that of inorganic organic hybrid perovskite solar cells. Moreover, the Bi2OS2 monolayer maintains good structural integrity up to 1000 K and has a relatively small exfoliation energy from its layered bulk. The excellent electronic and optical properties, together with high stability and great experimental possibility, render 2D Bi2OS2 a promising material for future nanoelectronic and optoelectronic applications.", "author_names": [ "Xiweng Zhang", "Bing Zhang Wang", "Xianghong Niu", "Yunhai Li", "Yunfei Chen", "Jinlan Wang" ], "corpus_id": 139856565, "doc_id": "139856565", "n_citations": 23, "n_key_citations": 0, "score": 1, "title": "Bi2OS2: a direct gap two dimensional semiconductor with high carrier mobility and surface electron states", "venue": "", "year": 2018 }, { "abstract": "Abstract The band gaps of isostructural Bi 2 OS 2 and LaOBiS 2 were examined using optical absorption and discussed with the band structures calculated based on the crystal structures determined using synchrotron X ray diffraction. The Bi 6p and S 3p orbitals in the Bi S plane were computationally predicted to constitute the bands near the Fermi level. The optical reflectance spectra of Bi 2 OS 2 and LaOBiS 2 showed optical band gaps of ~1.0 eV, which were close to the computationally calculated direct band gaps of ~0.8 eV. Our results show that Bi 2 OS 2 and LaOBiS 2 are semiconductors containing direct band gaps of 0.8 1.0 eV, and they are suggested to be candidates for optoelectronic materials in the near infrared region without highly toxic elements.", "author_names": [ "Akira Miura", "Yoshikazu Mizuguchi", "Takahiro Takei", "Nobuhiro Kumada", "Eisuke Magome", "Chikako Moriyoshi", "Yoshihiro Kuroiwa", "Kiyoharu Tadanaga" ], "corpus_id": 119223127, "doc_id": "119223127", "n_citations": 24, "n_key_citations": 0, "score": 1, "title": "Structures and optical absorption of Bi2OS2 and LaOBiS2", "venue": "", "year": 2016 }, { "abstract": "The band gaps of isostructural Bi2OS2 and LaOBiS2 were examined using optical absorption and discussed with the band structures calculated based on the crystal structures determined using synchrotron X ray diffraction. The Bi 6p and S 3p orbitals in the Bi S plane were computationally predicted to constitute the bands near the Fermi level. The optical reflectance spectra of Bi2OS2 and LaOBiS2 showed optical band gaps of ca. 1.0 eV, which were close to the computationally calculated direct band gaps of ca. 0.8 eV. Our results show that Bi2OS2 and LaOBiS2 are semiconductors containing direct band gaps of 0.8 1.0 eV, and they are suggested to be candidates for optoelectronic materials in the near infrared region without highly toxic elements.", "author_names": [ "Akira Miura", "Yoshikazu Mizuguchi", "Takahiro Takei", "Nobuhiro Kumada", "Eisuke Magome", "Chikako Moriyoshi", "Yoshihiro Kuroiwa", "Kiyoharu Tadanaga" ], "corpus_id": 124401262, "doc_id": "124401262", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Structures and Optical Properties of Bi2OS2 and LaOBiS2", "venue": "", "year": 2015 }, { "abstract": "The electron and phonon transport properties of layered bismuth oxychalcogenides Bi2OX2 (X S, Se) are studied by combining density functional theory calculation with the Boltzmann transport theory. It is found that Bi2OS2 and Bi2OSe2 are semiconductors with direct bandgaps of 0.86 eV and 0.63 eV, respectively. A large Seebeck coefficient is found in both p and n doped Bi2OX2 (X S, Se) at 300 K together with their low phonon thermal conductivity (kph) Through a detailed analysis of the phonon dispersion relation, relaxation time, and joint density of states, we find that the low frequency modes contribute dominantly to kph than the high frequency modes. Owing to the high Seebeck coefficient and the low kph, the largest figure of merit (ZT) value can reach 0.5 for the Bi2OX2. The results are useful for further tuning the thermoelectric properties of Bi2OX2 (X S, Se)", "author_names": [ "Hongyue Song", "Xu-Jin Ge", "Jing-Tao Lu" ], "corpus_id": 230637316, "doc_id": "230637316", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "First principles study on the electron and phonon transport properties of layered Bi2OX2 (X S, Se)", "venue": "", "year": 2020 }, { "abstract": "We have explored the optoelectronic structure and related thermoelectric properties of Bi2OX2 (X S, Se, Te) using density functional theory and spin orbit coupling (SOC) We report herein calculations of the bandgap of these bismuth sulfides/oxysulfides to participate in the recent debate regarding such values. The generalized gradient approximation calculations corrected using the SOC scheme estimated bandgaps of 0.950 eV, 0.635 eV, and 0.441 eV for Bi2OS2, Bi2OSe2, and Bi2OTe2, respectively, in close agreement with experimental results and showing better accuracy compared with available theoretical calculations. This bandgap range shows the potential use of Bi2OX2 for solar cell applications. Hence, we derived their optical and thermoelectric properties. Similarly to one of the parent materials, Bi2S3, a semiconductor with special photovoltaic and thermoelectric properties, the present derivatives Bi2OX2 show promising characteristics for exploration in the near future for use in solar cells and thermoelectric devices.", "author_names": [ "Sikander Azam", "Saleem Ayaz Khan", "Souraya Goumri-Said" ], "corpus_id": 103184759, "doc_id": "103184759", "n_citations": 11, "n_key_citations": 0, "score": 0, "title": "Optoelectronic and Thermoelectric Properties of Bi2OX2 (X S, Se, Te) for Solar Cells and Thermoelectric Devices", "venue": "Journal of Electronic Materials", "year": 2018 } ]
Gd2CoMnO6
[ { "abstract": "The double perovskite gadolinium cobalt manganate (Gd2CoMnO6) ceramic material was prepared via mixed oxide route. The preliminary X ray structural study reveals that the material was found in monoclinic structure. We have found the small voids with almost uniform distribution of grains from the microstructural analysis. Analysis of the dielectric and electrical data, collected in a wide range of frequency range (1 kHz 1 MHz) and temperature (25 500 degC) has provided many interesting results. We have discussed frequency dependence dielectric parameter by Maxwell Wagner model. We found that the room temperature dielectric constant at 1 kHz frequency is 300 and tangent loss is nearly equal to 2. A dielectric anomaly (ferroelectric paraelectric phase transition) was found in the temperature dependence of dielectric study. The study of diffuse phase transition exhibits the existence of relaxation process in the compound. In the Nyquist plots, both grain and grain boundary effects are observed which is characterized by (RQC) and (RQC)(RC) circuits. As the resistance decreases with increase of temperature, the material shows the semiconductor behavior. The existence of non Debye type of relaxation mechanism in the material is confirmed by the depression angle. The frequency dependence of electric conductivity has been studied using the Jonscher's power law, in which the frequency exponent n 1) signifies the translational motion with involvement of an intuitive hopping of charge carriers. The leakage current and conduction mechanism follow the space charge limited conduction phenomenon. The low leakage current density may be suitable for high temperature applications.", "author_names": [ "Rutuparna Das", "Ram Naresh Prasad Choudhary" ], "corpus_id": 219985574, "doc_id": "219985574", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Synthesis and characterization of rare earth ion based double perovskite: Gd2CoMnO6", "venue": "Journal of Materials Science: Materials in Electronics", "year": 2020 }, { "abstract": "Abstract Structural, magnetization, phonon behavior, and dielectric response of nano crystalline Gd2CoMnO6 have been presented in this paper. The study shows that the material crystallizes in P21/n phase group of monoclinic crystal structure. XPS measurement shows Co2+ and Mn4+ oxidation states are present in the sample. Magnetization study reveals that sample undergoes a ferromagnetic ordering of Co2+ and Mn4+ magnetic ions around T c 132 K. Raman study shows the presence of spin phonon coupling in Gd2CoMnO6. Dielectric study reveals that the sample shows large dielectric constant and strong dispersion in mid frequency range. The dielectric loss shows there are two relaxation processes present in the material with different relaxation time and which are driven by thermally activated relaxation mechanics. Further, the Nyquist plot and AC conductivity study shows that this sample is non Debye's in nature.", "author_names": [ "Ilyas Noor Bhatti", "Imtiaz Noor Bhatti", "Rabindra Nath Mahato", "M A H Ahsan" ], "corpus_id": 224980986, "doc_id": "224980986", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Structure, magnetism and dielectric study of nano crystalline Gd2CoMnO6", "venue": "", "year": 2020 }, { "abstract": "Abstract Gd2CoMnO6 and Y2CoMnO6 double perovskite ceramics were obtained from the polymeric precursors method and investigated by X ray diffraction, X ray photoelectron spectroscopy (XPS) scanning electron microscopy (SEM) Raman and Fourier Transform Infrared (FTIR) spectroscopies. Our results show that these samples present similar structural and vibrational characteristics that are fully compatible with a monoclinic structure belonging to the P21/n space group, with ordered Co2+ and Mn4+ cations. Infrared reflectivity spectroscopy was employed to investigate the polar phonon features and to determine the intrinsic dielectric response of the materials. In particular, the extrapolated dielectric constants at the lower frequency infrared limit showed to be independent on the particle size, and were determined as e intr 17.8 and 16.0, for Gd2CoMnO6 and Y2CoMnO6, respectively. Otherwise, it is shown that for smaller RE radius the FTIR bands become more evidenced, due to a higher octahedral rotation and lower Co O Mn angle into the distorted monoclinic structure.", "author_names": [ "R X Silva", "R M Almeida", "Roberto Luiz Moreira", "Roberto M Paniago", "Marcos Vinicius dos Santos Rezende", "C W A Paschoal" ], "corpus_id": 139173764, "doc_id": "139173764", "n_citations": 9, "n_key_citations": 0, "score": 1, "title": "Vibrational properties and infrared dielectric features of Gd2CoMnO6 and Y2CoMnO6 double perovskites", "venue": "Ceramics International", "year": 2019 }, { "abstract": "Abstract 3d based double perovskite (DP) oxides having great research interest due to their physical properties with some great technological application. Magnetodielectric, magnetocaloric effect, ferroelectric, exotic magnetic phases etc are some properties that double perovskite materials shows, thus received attention of researchers. Magnetic refrigeration is the great cooling technology based on magnetocaloric effect due to high energy efficiency and environmental friendly. Recently, it is found that Gadolinium (Gd) have magnetic refrigerant properties because of large magnatochloric effects at room temperature. In this paper we present the double perovskite Gd2CoMnO6 nano crystalline which was prepared by sol gel method and its magnetic properties studied by vibrating sample magnetometer (VSM) There is a paramagnetic to ferromagnetic phase transition observed in the sample. We found that paramagnetic Curie Weiss temperature of Gd2CoMnO6 is around Tc 131.27 K. Further, temperature dependent inverse magnetic susceptibility (kh 1) shows deviation from curie Weiss behavior around TG 213 K which is depicts that Griffiths phase singularities is present in this material.", "author_names": [ "Ilyas Noor Bhatti", "Rabindra Nath Mahato", "Imtiaz Noor Bhattib", "M A H Ahsan" ], "corpus_id": 201327099, "doc_id": "201327099", "n_citations": 3, "n_key_citations": 0, "score": 0, "title": "Synthesis and Magnetic Study of Nano Crystalline Gd2CoMnO6", "venue": "", "year": 2019 }, { "abstract": "Abstract Gd2CoMnO6 nanostructures (GCMO NSs) were synthesized through a simple combustion method at 800 degC calcination temperature in the presence of the different amino acids, including phenylalanine, beta alanine, leucine, valine and glycine, as combustion, gelling and stabilizing agents. In this work, metal nitrate salts were used as starting materials and the Gd:Co:Mn molar ratio was selected to be 2:1:1. The beta alanine was selected as the optimum amino acid. Effects of type of the amino acid and calcination temperature on the morphology and particle size of the products were investigated. X ray diffraction (XRD) Fourier transform infrared spectroscopy (FTIR) ultra violet diffuse reflectance spectroscopy (UV DRS) scanning electron microscopy (SEM) transmission electron microscopy (TEM) energy dispersive X ray (EDX) and vibrating sample magnetometer (VSM) were used for characterization and investigation of the applications of GCMO NSs. VSM results showed an antiferromagnetic behavior for the GCMO NSs. Optical properties of the NSs were investigated and the optical band gap of them was found to be 3.28 eV. Also photocatalytic properties of the GCMO NSs for the degradation of methyl violet, erythrosine and eriochrome black T were investigated.", "author_names": [ "Reza Mohassel", "Azam Sobhani", "Mojgan Goudarzi", "Masoud Salavati-Niasari" ], "corpus_id": 139537590, "doc_id": "139537590", "n_citations": 10, "n_key_citations": 0, "score": 0, "title": "Amino acid modified combustion synthesis, characterization and investigation of magnetic, optical and photocatalytic properties of Gd2CoMnO6 nanostructures", "venue": "", "year": 2018 }, { "abstract": "GCMO NSs were synthesized by the reaction of metal nitrate salts in the presence of stabilizing agent and PG, by a Pechini method. Citric acid, maleic acid, succinic acid and 1,3,5 benzenetricarboxylic acid were used as stabilizing agents. The structure, morphology, optical, magnetic and photocatalytic properties of the GCMO NSs were investigated using various characterization techniques. Effects of type of stabilizing agent, the molar ratio of stabilizing agent:PG and also calcination temperature on particle size and morphology of the products were investigated. Also the influence of kind of pollutant on photocatalytic behavior of GCMO NSs was evaluated.", "author_names": [ "Reza Mohassel", "Azam Sobhani", "Masoud Salavati-Niasari", "Mojgan Goudarzi" ], "corpus_id": 49477933, "doc_id": "49477933", "n_citations": 13, "n_key_citations": 0, "score": 0, "title": "Pechini synthesis and characteristics of Gd2CoMnO6 nanostructures and its structural, optical and photocatalytic properties.", "venue": "Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy", "year": 2018 }, { "abstract": "The phenomenon of magnetocaloric effect occurring around the ordering temperatures for Gd2 xSrxCoMnO6 (x 0 and 0.5) has been investigated in order to disclose the effects of Sr substitution on the individual collinear Gd spin order. It is shown that 25% Sr substitution of Gd ions significantly suppresses the independent spin order, leading to enhancement of ferromagnetism. As a result, magnetic entropy change DSM) increases from +0.9 J kg 1 K 1 to +3.7 J kg 1 K 1 at Curie temperature for a change in magnetic field (DH) 6.9 T. On the other hand, the DSM changes sign at Neel temperature due to the effect of Sr substitution. We have also observed noticeably large DSM +25.84 J kg 1 K 1) and +21.01 J kg 1 K 1) for DH 6.9 T at 4f 4f negative coupling temperature (T 10 K) of x 0 and x 0.5 samples, respectively.The phenomenon of magnetocaloric effect occurring around the ordering temperatures for Gd2 xSrxCoMnO6 (x 0 and 0.5) has been investigated in order to disclose the effects of Sr substitution on the individual collinear Gd spin order. It is shown that 25% Sr substitution of Gd ions significantly suppresses the independent spin order, leading to enhancement of ferromagnetism. As a result, magnetic entropy change DSM) increases from +0.9 J kg 1 K 1 to +3.7 J kg 1 K 1 at Curie temperature for a change in magnetic field (DH) 6.9 T. On the other hand, the DSM changes sign at Neel temperature due to the effect of Sr substitution. We have also observed noticeably large DSM +25.84 J kg 1 K 1) and +21.01 J kg 1 K 1) for DH 6.9 T at 4f 4f negative coupling temperature (T 10 K) of x 0 and x 0.5 samples, respectively.", "author_names": [ "R C Sahoo", "S Das", "Tapan Kumar Nath" ], "corpus_id": 125764431, "doc_id": "125764431", "n_citations": 6, "n_key_citations": 0, "score": 0, "title": "Role of Gd spin ordering on magnetocaloric effect and ferromagnetism in Sr substituted Gd2CoMnO6 double perovskite", "venue": "", "year": 2018 }, { "abstract": "The magnetocaloric effect (MCE) is described by the change in temperature of a material by magnetic field variation and is a crucial subject in magnetism; it is motivated by the desire to enhance energy efficient magnetic refrigeration for clean technology. Despite the recent discovery of the giant cryogenic MCE in double perovskites, the role of magnetic anisotropy has not yet been clearly discussed, because of the averaging effect of polycrystalline samples. Here, we investigated the anisotropic MCE in the single crystal double perovskite Gd2CoMnO6. In addition to the ferromagnetic order of the Co2+ and Mn4+ moments, the large Gd3+ moments align below TGd 21 K, exhibiting an isotropic nature. Because of the intricate temperature development of magnetically hysteretic behaviour and metamagnetism, the change in magnetic entropy along the c axis appears to be relatively small. On the contrary, the smaller but almost reversible magnetization perpendicular to the c axis leads to a large MCE with a maximum entropy change of 25.4 J/kg*K. The anisotropic MCE generates a giant rotational MCE, estimated as 16.6 J/kg*K. Our results demonstrate the importance of magnetic anisotropy for understanding the MCE and reveal essential clues for exploring suitable magnetic refrigerant compounds aiming at magnetic functional applications.", "author_names": [ "Jae Young Moon", "M K Kim", "Y J Choi", "Nara Lee" ], "corpus_id": 205629687, "doc_id": "205629687", "n_citations": 36, "n_key_citations": 0, "score": 0, "title": "Giant Anisotropic Magnetocaloric Effect in Double perovskite Gd2CoMnO6 Single Crystals", "venue": "Scientific Reports", "year": 2017 }, { "abstract": "Abstract Double perovskite R 2 CoMnO 6 systems, with magnetically active rare earth (R) elements, have attracted much attention because of their interesting field sensitive magnetic phenomena and remarkable physical properties. The perovskite compound Gd 2 CoMnO 6 exhibits a field induced metamagnetic phase transition from ferrimagnetic to long range ferromagnetic (FM) ordering below a critical temperature of T C ~112 K. It also shows polarization of the Co/Mn magnetic sublattice to the Gd moments resulting in antiferromagnetic (AFM) like behaviour at T N ~47 K. Further, the large change in magnetization at low temperatures of T 3+ excitations. A sharp peak at T C in AC susceptibility measurements reveals that susceptibility is the sum of the true critical maximum and Hopkinson peak contributions. Below T N ~47 K, the 4 f 3 d negative exchange interaction is responsible for the observed antiferromagnetic spin polarizations; consequently the exchange bias (EB) effect originates from the unidirectional anisotropy induced at the antiferromagnetic/ferromagnetic interface.", "author_names": [ "J Krishna Murthy", "Adyam Venimadhav" ], "corpus_id": 136076399, "doc_id": "136076399", "n_citations": 23, "n_key_citations": 0, "score": 0, "title": "4f 3d exchange coupling induced exchange bias and field induced Hopkinson peak effects in Gd2CoMnO6", "venue": "", "year": 2017 }, { "abstract": "We have investigated magnetocaloric effect in double perovskite Gd2NiMnO6 (GNMO) and Gd2CoMnO6 (GCMO) samples by magnetic and heat capacity measurements. Ferromagnetic ordering is observed at ~130 K ~112 K) in GNMO (GCMO) while the Gd exchange interactions seem to dominate for T 20 K. In GCMO, below 50 K, an antiferromagnetic behaviour due to 3d 4f exchnage interaction is observed. A maximum entropy \\Delta}SM) and adiabatic temperature change of ~35.5 J Kg 1 K 1 ~24 J Kg 1 K 1) and 10.5 K (6.5 K) is observed in GNMO (GCMO) for a magnetic field change of 7 T at low temperatures. Absence of magnetic and thermal hysteresis and their insulating nature make them promising for low temperature magnetic refrigeration.", "author_names": [ "J Krishna Murthy", "K Devi Chandrasekhar", "Sudipta Mahana", "Dinesh Topwal", "Adyam Venimadhav" ], "corpus_id": 119256318, "doc_id": "119256318", "n_citations": 45, "n_key_citations": 0, "score": 0, "title": "Giant magnetocaloric effect in Gd2NiMnO6 and Gd2CoMnO6 ferromagnetic insulators", "venue": "", "year": 2015 } ]
organic semiconductor environment
[ { "abstract": "Development of carbon neutral and sustainable energy sources should be considered as a top priority solution for the growing worldwide energy demand. Photovoltaics are a strong candidate, more specifically, organic photovoltaics (OPV) enabling the design of flexible, lightweight, semitransparent, and low cost solar cells. However, the active layer of OPV is, for now, mainly deposited from chlorinated solvents, harmful for the environment and for human health. Active layers processed from health and environmentally friendly solvents have over recent years formed a key focus topic of research, with the creation of aqueous dispersions of conjugated polymer nanoparticles arising. These nanoparticles are formed from organic semiconductors (molecules and macromolecules) initially designed for organic solvents. The topic of nanoparticle OPV has gradually garnered more attention, up to a point where in 2018 it was identified as a \"trendsetting strategy\" by leaders in the international OPV research community. Hence, this review has been prepared to provide a timely roadmap of the formation and application of aqueous nanoparticle dispersions of active layer components for OPV. We provide a thorough synopsis of recent developments in both nanoprecipitation and miniemulsion for preparing photovoltaic inks, facilitating readers in acquiring a deep understanding of the crucial synthesis parameters affecting particle size, colloidal concentration, ink stability, and more. This review also showcases the experimental levers for identifying and optimizing the internal donor acceptor morphology of the nanoparticles, featuring cutting edge X ray spectromicroscopy measurements reported over the past decade. The different strategies to improve the incorporation of these inks into OPV devices and to increase their efficiency (to the current record of 7.5% are reported, in addition to critical design choices of surfactant type and the advantages of single component vs binary nanoparticle populations. The review naturally culminates by presenting the upscaling strategies in practice for this environmentally friendly and safer production of solar cells.", "author_names": [ "Alexandre Holmes", "Elise Deniau", "Christine Lartigau-Dagron", "Antoine Bousquet", "Sylvain Chambon", "Natalie P Holmes" ], "corpus_id": 232017608, "doc_id": "232017608", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "Review of Waterborne Organic Semiconductor Colloids for Photovoltaics.", "venue": "ACS nano", "year": 2021 }, { "abstract": "Photocatalytic applications of halide perovskites have attracted increasing attention. However, lack of stability and lead toxicity of lead halide perovskites have hindered their applications. Metal halide double perovskite (DP) Cs2AgInCl6 is a stable, environment friendly semiconductor with direct band gap, and then the best promising alternative to lead halide perovskites. Here, the applications of Cs2AgInCl6 DP to photocatalytic degradation of organic pollutants have been developed, in which the octahedral Cs2AgInCl6 DP particles ~3.33 eV) were prepared by precipitation from acid solutions. The as prepared samples exhibit high photocatalytic activity, which can degrade about 98.5% of water insoluble carcinogen Sudan Red III in only 16 min, and have a good stability for 5 cycle operations. Furthermore, the Cs2AgInCl6 DP also can degrade Rhodamine B, Methyl orange and Methyl red efficiently, demonstrating a highly efficient and stable ethanol solvent based photocatalytic system for organic pollutants degradation. The high photocatalytic activity could be attributed to direct band gap and long carrier lifetime of Cs2AgInCl6 DP. These unique features of Cs2AgInCl6 DP indicate that it could have a good application prospect for photocatalytic degradation of organic pollutants.", "author_names": [ "Sen Li", "Wule Zhang", "Zhifeng Shi", "Di Wu", "Xu Chen", "Pei Lin", "Yongtao Tian", "Xinjian Li" ], "corpus_id": 233234266, "doc_id": "233234266", "n_citations": 2, "n_key_citations": 0, "score": 1, "title": "Highly efficient and stable photocatalytic activity of lead free Cs2AgInCl6 double perovskite for organic pollutant degradation.", "venue": "Journal of colloid and interface science", "year": 2021 }, { "abstract": "Heavy metal pollution in the environment poses a serious threat to the ecosystem and human health, which has attracted widespread attention. In this study, an octahedral structure composite composed of UiO 66 NH2 MOFs and semiconductor GaOOH materials has been prepared and used as electrode materials successfully. These composites can be used for the real time and online determination of Cd2+ Cu2+ Hg2+ and Pb2+ in real water samples simultaneously or alone via an electrochemical method. Zr MOF has a large and unique surface area that is beneficial to the adsorption and preconcentration of heavy metal ions. The experiment parameters such as pH, deposition potential, and deposition time were optimized. Under the optimized conditions, the electrochemical performances and practical applications of Zr MOF composites modified electrode have been investigated, which shows excellent wider linear range and lower detection limit (LOD) The results demonstrated excellent selectivity, reproducibility, stability and applicability for the detection of four metal ions. These superior features stem from the synergistic reaction mechanism of UiO 66 NH2 and GaOOH. In addition, it has been established a new detection strategy for heavy metal ions through the form of metal organic framework (MOF) composite in this work. It may provide a novel platform for the quantitative determination of heavy metal ions in various environmental samples.", "author_names": [ "Jing Ru", "Xuemei Wang" ], "corpus_id": 236959698, "doc_id": "236959698", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "GaOOH modified metal organic frameworks UiO 66 NH2: Selective and sensitive sensing four heavy metal ions in real wastewater by electrochemical method.", "venue": "Talanta", "year": 2021 }, { "abstract": "Technologies for wastewater remediation have been growing ever since the environmental and health concern is realised. Development of nanomaterials has enabled mankind to have different methods to treat the various kind of inorganic and organic pollutants present in wastewater from many resources. Among the many materials, semiconductor materials have found many environmental applications due to their outstanding photocatalytic activities. TiO2 and ZnO are more effectively used as photocatalyst or adsorbents in the withdrawal of inorganic as well as organic wastes from the wastewater. On the other hand, graphene is tremendously being investigated for applications in environmental remediation in view of the superior physical, optical, thermal and electronic properties of graphene nanocomposites. In this work, graphene TiO2 and graphene ZnO nanocomposites have been reviewed for photocatalytic wastewater treatment. The various preparation techniques of these nanocomposites have been discussed. Also, different design strategies for graphene based photocatalyst have been revealed. These nanocomposites exhibit promising applications in most of the water purification processes which are reviewed in this work. Along with this, the development of these nanocomposites using biomass derived graphene has also been introduced.", "author_names": [ "Kunal G Thakre", "Divya P Barai", "Bharat Apparao Bhanvase" ], "corpus_id": 236978129, "doc_id": "236978129", "n_citations": 1, "n_key_citations": 0, "score": 0, "title": "A review of graphene TiO2 and graphene ZnO nanocomposite photocatalysts for wastewater treatment.", "venue": "Water environment research a research publication of the Water Environment Federation", "year": 2021 }, { "abstract": "The recent and vigorous developments in semiconductor technology strictly request better quality and large quantity of ultrapure water (UPW) for their production. It is crucial to secure a large amount of raw water for the future development of UPW production. Using reclaimed water as alternative raw water source to produce UPW is therefore considered the feasible trend and solution for sustainable use of water resources towards a common future practice in UPW production. The challenge of using reclaimed water is due to its higher content of organic pollutants, especially small molecule organic pollutants such as urea, which are difficult to remove through traditional UPW production process. Consequently, improving the existing UPW production process to meet the water standard desired in the semiconductor industry is essential. This paper reviewed the current traditional processes for removing organic matters in UPW production, including ion exchange (IX) adsorption, granular activated carbon (GAC) adsorption, reverse osmosis (RO) and ultraviolet (UV) irradiation. The potential problems in the actual UPW production process were identified when using reclaimed water as raw water source. A new strategy of applying the advanced oxidation process (AOPs) to UPW production as a supplementary unit to guarantee UPW quality was proposed. Its feasibility and research focus were then analyzed and discussed in obtaining a new solution for a future development of the UPW production process.", "author_names": [ "Xinbo Zhang", "Yuanying Yang", "Huu Hao Ngo", "Wenshan Guo", "Haitao Wen", "Xiao Wang", "Jian-qing Zhang", "Tianwei Long" ], "corpus_id": 233484326, "doc_id": "233484326", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "A critical review on challenges and trend of ultrapure water production process.", "venue": "The Science of the total environment", "year": 2021 }, { "abstract": "The use of the anammox process for nitrogen removal has gained popularity across the world due to its low energy consumption and waste generation. Anammox reactors have been used to treat ammonium rich effluents such as chemical, pharmaceutical, semiconductor, livestock, and coke oven wastewater. Recently, full scale installations have been implemented for municipal wastewater treatment. The efficiency of biological processes is susceptible to inhibitory effects of pollutants present in wastewater. Considering the increasing number of emerging contaminants detected in wastewater, the impacts of the different types of pollutants on anammox bacteria must be understood. This review presents a compilation of the studies assessing the inhibitory effects of different wastewater pollutants towards anammox activity. The pollutants were classified as antibiotics, aromatics, azoles, surfactants, microplastics, organic solvents, humic substances, biodegradable organic matter, or metals and metallic nanoparticles. The interactions between the pollutants and anammox bacteria have been described, as well as the interactions between different pollutants leading to synergistic effects. We also reviewed the effects of pollutants on distinct species of anammox bacteria, and the main toxicity mechanisms leading to irreversible loss of anammox activity have been identified. Finally, we provided an analysis of strategies to overcome the inhibitory effects of wastewater pollutants on the nitrogen removal performance. We believe this review will contribute with essential information to assist the operation and design of anammox reactors treating different types of wastewaters.", "author_names": [ "Camila L Madeira", "Juliana Calabria de Araujo" ], "corpus_id": 236968080, "doc_id": "236968080", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Inhibition of anammox activity by municipal and industrial wastewater pollutants: A review.", "venue": "The Science of the total environment", "year": 2021 }, { "abstract": "A recent research emphasis has been placed on the development of highly crystallized nanostructures as a useful technology for many photocatalytic applications. With the unique construction of semiconductor transition metal oxide nanostructures in the form of nanopillars artificially designed pillar shaped structures grouped together in lattice type arrays the surface area for photocatalytic potential is increased and further enhanced through the introduction of dopants. This short review summarizes the work on improving the efficiency of photocatalyst nanopillars through increased surface area and doping within the applications of water splitting, removal of organic pollutants from the environment, photoswitching, soot oxidation, and photothermalization.", "author_names": [ "Jessica L Waite", "Julianna Hunt", "Haifeng Ji" ], "corpus_id": 231584879, "doc_id": "231584879", "n_citations": 1, "n_key_citations": 0, "score": 1, "title": "Improving Photocatalytic Performance Using Nanopillars and Micropillars", "venue": "Materials", "year": 2021 }, { "abstract": "Contact electrification activated triboelectric potential offers an efficient route to tuning the transport properties in semiconductor devices through electrolyte dielectrics, i.e. triboiontronics. Organic electrochemical transistors (OECTs) make more effective use of ion injection in the electrolyte dielectrics by changing the doping state of the semiconductor channel. However, the mainstream flexible/wearable electronics and OECT based devices are usually modulated by electrical signals and constructed in conventional geometry, which lack direct and efficient interaction between the external environment and functional electronic devices. Here, we demonstrate a fiber shaped triboiontronic electrochemical transistor with good electrical performances, including a current on/off ratio as high as 1286 with off current at ~nA level, the average threshold displacements (Dth) of 0.3 mm, the subthreshold swing corresponding to displacement (SSD) at 1.6 mm/dec, and excellent flexibility and durability. The proposed triboiontronic electrochemical transistor has great potential to be used in flexible, functional, and smart self powered electronic textile.", "author_names": [ "Shanshan Qin", "Huai Zhang", "Yichen Wei", "Xiaoxiao Zhu", "Ya Yang", "Qijun Sun" ], "corpus_id": 233218283, "doc_id": "233218283", "n_citations": 0, "n_key_citations": 0, "score": 0, "title": "Fiber Shaped Triboiontronic Electrochemical Transistor", "venue": "Research", "year": 2021 }, { "abstract": "With the rapid development of society, the burden of energy and the environment is becoming more and more serious. Photocatalytic hydrogen production, the photosynthesis of organic fuel, and the photodegradation of pollutants are three effective ways to reduce these burdens using semiconductor photocatalysts. To improve the reaction efficiency of photocatalysts, a small amount of cocatalyst is often added when photocatalysts participate in the synthesis or decomposition reaction. The addition of this small amount of cocatalyst is like a finishing touch, significantly increasing the activity of the photocatalysts. However, in our common study of photocatalysis, we often pay attention to the study of photocatalysts but ignore the study of cocatalysts. Herein, we summarize the recent application research on cocatalysts in the field of photocatalysis, starting from the types, preparation methods, and reaction mechanisms among others, to remind researchers of the matters needing attention when using cocatalysts.", "author_names": [ "Gang Zhao", "Xijin Xu" ], "corpus_id": 235379517, "doc_id": "235379517", "n_citations": 0, "n_key_citations": 0, "score": 1, "title": "Cocatalysts from types, preparation to applications in the field of photocatalysis.", "venue": "Nanoscale", "year": 2021 }, { "abstract": "Over the past several decades, organic conjugated materials as semiconductors in organic field effect transistors (OFETs) have attracted more and more attention from the scientific community due to their intriguing properties of mechanical flexibility and solution processability. However, the device fabrication technique, design, and synthesis of novel organic semiconductor materials with high charge carrier mobility is crucial for the development of high performance OFETs. In the past few years, more and more novel materials were designed and tested in the OFETs. Among which, diketopyrrolopyrrole (DPP) and its derivatives, as the electron acceptors to build donor acceptor (D A) typed materials, are the perspective. In this article, recently reported molecules regarding the DPP and its derivatives for OFETs application are reviewed. In addition, the relationship between the chemical structures and the performance of the device are discussed. Furthermore, an outlook of DPP based materials in OFETs with a future design concept and the development trend are provided.", "author_names": [ "Xiangyu Zou", "Shuaiwei Cui", "Junqiang Li", "Xueling Wei", "Meng Zheng" ], "corpus_id": 233228722, "doc_id": "233228722", "n_citations": 2, "n_key_citations": 0, "score": 0, "title": "Diketopyrrolopyrrole Based Organic Semiconductor Materials for Field Effect Transistors", "venue": "Frontiers in Chemistry", "year": 2021 } ]

Semiconductor Dataset

This dataset is a collection of Scientific Report / Paper related to Semiconductor.

Dataset Details

This dataset was curated from the SciRepEval dataset and only using any information that related to Semiconductor fields.

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Models trained or fine-tuned on sitloboi2012/semiconductor_scirepeval_v1