- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Run-to-run control of PECVD systems: Application to a multiscale three-dimensional CFD model of silicon thin film deposition
摘要： Deposition of amorphous silicon thin films via plasma-enhanced chemical vapor deposition (PECVD) and batch-to-batch operation under run-to-run control of the associated chambered reactor are presented in this work using a recently developed multiscale, three-dimensional in space, computational fluid dynamics model. Macroscopic reactor scale behaviors are linked to the microscopic growth of amorphous silicon thin films using a dynamic boundary which is updated at each time step of the transient in-batch simulations. This novel workflow is distributed across 64 parallel computation nodes in order to reduce the significant computational demands of batch-to-batch operation and to allow for the application and evaluation in both radial and azimuthal directions across the wafer of a benchmark, run-to-run based control strategy. Using 10 successive batch deposition cycles, the exponentially weighted moving average algorithm, an industrial standard, is demonstrated to drive all wafer regions to within 1% of the desired thickness set-point in both radial and azimuthal directions across the wafer surface. This is the first demonstration of run-to-run control in reducing azimuthal film nonuniformity. Additionally, thin film uniformity is shown to be improved for poorly optimized PECVD geometries by manipulating the substrate temperature alone, without the need for re-tooling of the equipment.
关键词： thin film silicon solar cells,parallel computing,multiscale modeling,computational fluid dynamics,run-to-run control,thin film growth
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Radiation of the Luminous Flux Into the Upper Half-Space in Wils - Building Design
摘要： The article focuses on the further verification of the software goniophotometer in the BUILDING DESIGN computational program in terms of the possibility of calculating the radiation of the liminous flux flowing into the upper half- space from public lighting systems [1]. Software goniophotometer was tested by the previous verification for the accuracy of calculations of the direct and indirect component of luminaire luminous flux. The superstructure was conceived as the possibility of inserting a network of calculating points in the shape of a sphere. We can imagine the points showing normal illuminance towards the centre of the sphere as a lux meter sensor. The system thus designed duplicates the function of a real goniophotometer, a photometric laboratory instrument that measures luminous intensity or luminous intensity curves. The principle of a goniophotometer is that it allows to measure the luminous intensity in different planes and at different angles, which can be easily interpreted by a sphere with a network of calculation points. The density of the calculation points can be entered in an angular step according to the standard luminaire measurement plan C, γ. The goal of implementing such a network of calculation points is to extend the possibilities of a computational program for modelling the luminous intensity curves of existing luminaires as well as newly composed luminaires. The main goal is calculating the radiation of the liminous flux flowing into the upper half-space from the outdoor lighting systems. It will be the basis for further astronomical calculations that focus on distracting light and increased sky luminance. Based on the testing, it will be possible to create model of lighting system in some city or district of the city by inserting LDT data of real luminaires, thus creating a real lighting system with real building models. From the resulting model, it will be possible to quantify the proportion of the direct and indirect luminous flux flowing into the upper half-space.
关键词： sodium lighting system,modeling,radiation curves,LED lighting system,software goniophotometer,upper half-space
更新于2025-09-23 15:21:21
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[IEEE 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Trebic, Czech Republic (2018.9.18-2018.9.20)] 2018 VII. Lighting Conference of the Visegrad Countries (Lumen V4) - Bended Light-Guide Modeling Under Broken Cloud Arrays
摘要： Bended light-guides represent an effective way of transporting of daylight into interiors of buildings, which can not be illuminated by vertical or roof windows. The effectivity of using those kind of devices depends on their physical parameters (length, diameter, band orientation, inner reflectance). But dependence on exterior properties, such as position of Sun, turbidity of atmosphere and mainly the presence of broken cloud arrays, is prior. Experimental approach of describing behavior of a light-guide is practically impossible, because of rapid changes of exterior conditions and of unrepeatability of measurements. Therefore, there is a need of numerical modeling as accurate as possible, which takes into account a wide range of sky states and variable configuration of light-guide. So far, most of such modeling were based on using empirical models, while our approach includes local state of the atmosphere and also 3D light-guide. This contribution is focused on determining the efficiency of the bended light-guides with different bend angles and orientation of their upper part by various levels of cloud fractions and positions of Sun. As a modeling tool, a link between the programs Unisky Simulator and Holigilm was created. Unisky Simulator is designed to model sky luminance distributions for arbitrary meteorological conditions and Holigilm enables calculations of light transmittance through the bended light-guides.
关键词： bended light guide,numerical modeling,sky luminance distribution,cloud fraction
更新于2025-09-23 15:21:21
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GaN Transistors for Efficient Power Conversion || Modeling and Measurement of GaN Transistors
摘要： The previous chapter focused on the layout parasitics that are important when using GaN transistors, and showed methods of minimizing these parasitics for layouts with various levels of complexity. In this chapter, the focus will be on how best to understand and predict the actual in-circuit behavior of the GaN transistors once the layout has been completed. Although measurement and modeling are very different, they complement each other when attempting to better understand real-world behavior. The initial discussion will focus on the electrical and thermal modeling of GaN transistors, and conclude with discussion of the requirements and limitations when directly measuring in-circuit behavior.
关键词： power conversion,electrical modeling,GaN transistors,measurement,modeling,thermal modeling
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Communication and Electronics Systems (ICCES) - Coimbatore, India (2019.7.17-2019.7.19)] 2019 International Conference on Communication and Electronics Systems (ICCES) - Design and performance analysis of WDM optical Communication system with EDFA-DCF and FBG for dispersion compensation using $8\mathrm{x}5$ Gbps data rate
摘要： The way in which electromagnetic ?elds are transmitted and received by ground penetrating radar (GPR) antennas is crucial to the performance of GPR systems. Simple antennas have been characterized by analyzing their radiation patterns and directivity. However, there have been limited studies that combine real GPR antennas with realistic environments, which is essential to capture the complex interactions between the antenna and surroundings. We have investigated the radiation characteristics and sensitivity of a GPR antenna in a range of lossy dielectric environments using both physical measurements and a three-dimensional (3-D) ?nite-difference time-domain (FDTD) model. Experimental data were from measured responses of a target positioned at intervals on the circumference of a circle surrounding the H-plane of the antenna. A series of oil-in-water emulsions as well as tap water were used to simulate homogeneous materials with different permittivities and with complex conductivities. Numerical radiation patterns were created utilizing a detailed 3-D FDTD model of the antenna. Good correlation was shown between the experimental results and modeled data with respect to the strength of the main lobe within the critical angle window. However, there are discrepancies in the strength of main lobe at shallow angles. In all the dielectrics, the main lobes are generally broad due to the near-?eld observation distance but, as expected, become narrower with increasing permittivity. These results provide con?dence for further use of the FDTD antenna model to investigate scenarios such as larger observation distances and heterogeneous environments that are dif?cult to study experimentally.
关键词： electromagnetic modeling,Antenna measurements,?nite-difference time-domain (FDTD),antenna radiation patterns,broadband antennas
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE 3rd Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) - Chongqing, China (2019.10.11-2019.10.13)] 2019 IEEE 3rd Advanced Information Management, Communicates, Electronic and Automation Control Conference (IMCEC) - Efficient Offline Programming Method for Remote Laser Assisted Drilling
摘要： A better understanding of the degradation modes and rates for photovoltaic (PV) modules is necessary to optimize and extend the lifetime of these modules. Lifetime and degradation science (L&DS) is used to understand degradation modes, mechanisms and rates of materials, components and systems to predict lifetime of PV modules. A PV module lifetime and degradation science (PVM L&DS) model is an essential component to predict lifetime and mitigate degradation of PV modules using reproducible open data science. Previously published accelerated testing data from Underwriter Laboratories on PV modules with fluorinated polyester backsheets, which included eight modules that were exposed up to 4000 hrs of damp heat (85% relative humidity at 85 ?C) and eight exposed up to 4000 hrs of ultraviolet light (80 W/m2 of 280–400 nm wavelengths at 60 ?C) (UV preconditioning) were used to determine statistically significant relationships between the applied stresses and measured responses. There were 15 different variables tracking aspects of system performance, degradation mechanisms, component metrics and time. Modules were analyzed for three system performance metrics (fill factor, peak power, and wet insulation). The results were statistically analyzed to identify variable transformations, statistically significant relationships (SSRs) and to develop the PVM L&DS model informed by a generalization of structural equation modeling techniques. The SSRs and significant model coefficients, combined with domain analytics, incorporating materials science, chemistry, and physics expertise, produced a pathway diagram ranking the variables’ impact on the system performance, which were iteratively examined using sound statistical analysis and diagnostics. The SSRs determined from the damp heat exposure for the system response of Pmax corresponded to the degradation pathway of polyester terephthalate (PET) and ethylene vinyl acetate (EVA) hydrolysis. A linear change point for the damp heat exposure with the system response of Pmax was determined to be 1890 hrs. The UV preconditioning exposure did not induce sufficient degradation shown by the quality of the R2 values for many of the best fitting models. This exemplifies the development of a methodology to determine rank ordered lifetime and degradation pathways present in modules and their effects on module performance over lifetime.
关键词： structural equation modeling,statistical analytics,Photovoltaics,lifetime and degradation science
更新于2025-09-23 15:21:01
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[IEEE GLOBECOM 2019 - 2019 IEEE Global Communications Conference - Waikoloa, HI, USA (2019.12.9-2019.12.13)] 2019 IEEE Global Communications Conference (GLOBECOM) - Stereo Ranging Method Using LED Transmitter for Visible Light Communication
摘要： At the request of the Domestic Nuclear Detection Office (DNDO), a Study Committee comprised of representatives from the American Physical Society, Panel on Public Affairs, the IEEE, and Nuclear and Plasma Sciences Society performed a technical review of the DNDO Transformational and Applied Research Directorate (TARD) R&D program. TARD’s principal objective is to address gaps in the Global Nuclear Detection Architecture (GNDA) through improvements in the performance, cost, and operational burden of detectors and systems. The charge to the Study Committee was to investigate the existing TARD R&D plan and portfolio, recommend changes to the existing plan, and recommend possible new R&D areas and opportunities. This report is the result of an independent, detailed analysis of the current R&D plan and includes, for each application area, observations, and recommendations to focus future investments within the context of the TARD mission.
关键词： radiation detection,Algorithms and modeling,nuclear forensics,shielded nuclear materials
更新于2025-09-23 15:21:01
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[IEEE 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Brasov, Romania (2019.11.3-2019.11.6)] 2019 8th International Conference on Renewable Energy Research and Applications (ICRERA) - Stable Operation of an Automotive Photovoltaic System under Moving Shadows
摘要： This paper presents a simple mathematical expression to model the effect of statistical dopant fluctuations on threshold voltage (Vth) of junction field-effect transistors (JFETs). The random discrete doping (RDD) in the active device area is used to derive an analytical model to compute the standard deviation, σ Vth,RDD of the Vth-distribution for any arbitrary channel doping profiles. The model shows that the Vth-variability in JFETs depends on the active device area, channel doping concentration, and the depth of the channel depletion region of the gate/channel pn-junction. The model is applied to compute σ Vth,RDD for symmetric and asymmetric source/drain double-gate n-channel JFETs. The simulation results show that the model can be used for predicting Vth-variability in JFETs.
关键词： statistical dopant fluctuations,random discrete doping,process variability in JFETs,modeling threshold voltage variability,JFET threshold voltage variability,Junction field-effect transistor (JFET)
更新于2025-09-23 15:21:01
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Performance modeling and analysis of high-concentration multi-junction photovoltaics using advanced hybrid cooling systems
摘要： This paper presents the performance modeling and analysis of the high-concentration multi-junction photovoltaic cells, using either constant-width one-section or two-stepwise microchannels-jet impingement hybrid cooling system. The performance simulation and analysis of the cells are conducted using a three dimensional-Computational Fluid Dynamics program for various operating parameters, including water flow rate (100–1300 mL/min.), inlet water temperature (10–80 °C), and heat flux (10–90 W/cm2 corresponding to concentration ratios of 250–2250). The thermal and electrical characteristics of the cells are correlated in dimensionless form as functions of the direct normal irradiance and the operating and geometrical parameters of the hybrid cooling systems. The developed high-quality explicit performance model correlations assist in the design, performance prediction, and selection of operation strategy of photovoltaic cells. The results indicated that the generated and net output power is directly proportional to the applied heat flux (concentration ratio) and inversely proportional to the inlet water temperature. Temperature uniformity of the photovoltaic base enhances with the water flow rate, deteriorates with heat flux, and less affected by the inlet temperature, particularly for the two-sections cooling system. The pumping power increases with water flow rate and decreases as both inlet temperature or heat flux increases. Heat transfer characteristics enhance significantly with water flow rate, moderately with inlet water temperature and slightly with heat flux.
关键词： Photovoltaic performance modeling,High-concentration multi-junction photovoltaic,Operating parameters,Microchannels heat sink,Electrical power correlations
更新于2025-09-23 15:21:01
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Analysis of High-Temperature Carrier Transport Mechanisms for High Al-Content Al <sub/>0.6</sub> Ga <sub/>0.4</sub> N MSM Photodetectors
摘要： We propose a generative model for robust tensor factorization in the presence of both missing data and outliers. The objective is to explicitly infer the underlying low-CANDECOMP/PARAFAC (CP)-rank tensor capturing the global information and a sparse tensor capturing the local information (also considered as outliers), thus providing the robust predictive distribution over missing entries. The low-CP-rank tensor is modeled by multilinear interactions between multiple latent factors on which the column sparsity is enforced by a hierarchical prior, while the sparse tensor is modeled by a hierarchical view of Student-t distribution that associates an individual hyperparameter with each element independently. For model inference under a fully Bayesian treatment, which can effectively prevent the overfitting problem and scales linearly with data size. In contrast to existing related works, our method can perform model selection automatically and implicitly without the need of tuning parameters. More specifically, it can discover the groundtruth of CP rank and automatically adapt the sparsity inducing priors to various types of outliers. In addition, the tradeoff between the low-rank approximation and the sparse representation can be optimized in the sense of maximum model evidence. The extensive experiments and comparisons with many state-of-the-art algorithms on both synthetic and real-world data sets demonstrate the superiorities of our method from several perspectives.
关键词： tensor factorization,robust factorization,tensor completion,video background modeling,variational Bayesian (VB) inference,Rank determination
更新于2025-09-23 15:21:01