添加剂对单晶硅太阳电池表面织构化的影响

在传统的氢氧化钾/水/乙醇制绒体系中添加酸类(酒石酸,硼酸)、表面活性剂(甲基纤维素、十二烷基磺酸钠、聚乙二醇PEG400)等添加剂,研究了添加剂含量对制绒面形貌和反射率的影响。研究表明,制绒液中酒石酸质量浓度为400×10-6时制绒效果最好,硅片反射率降低到原始硅片的55.48%;混合添加100×10-6酒石酸、200×10-6硼酸的制绒效果更加明显,反射率达到原始硅片的40.81%。而在酒石酸/硼酸混合体系中添加质量分数为0.2%的表面活性剂PEG400时制绒效果较好,硅片反射率降低为原始硅片反射率的40.45%。     

QE测量在晶体硅太阳电池研究中的应用

介绍了量子效率测量的原理以及此项技术在太阳电池研究中的应用。通过对晶硅太阳电池量子效率的测量,分析了不同设备和工艺参数对太阳电池量子效率的影响,为优化生产工艺,提高电池性能提供有力的依据。     

太阳电池用晶体硅片及其技术标准发展现状

介绍了目前太阳电池用晶体硅片及其技术标准的发展现状,分析了单多晶硅片的现状及发展趋势,分别介绍了单晶硅片向N型硅片、薄片化及大尺寸发展,以及多晶硅片向高效多晶方向迈进的趋势;梳理了单多晶硅片技术标准的现状与发展趋势,分析了单多晶硅片技术标准中存在的技术要求落后、参数设定包容性差,适用性偏低等诸多问题,对了解太阳能用单多晶硅片业内情况及单多晶硅片相应标准的制定都有重要的指导意义。     

太阳能电池中纳米TiO2多孔膜的制备

纳米TiO2多孔膜具有非常大的比表面积，其表面上吸附大量的染料分子进行敏化以后可以有效地吸收太阳光，并将其转化为电能。本介绍了染料敏化的纳米TiO2太阳能电池的基本结构和工作原理，以及染料敏化的纳米TiO2多孔膜的制备及研究现状。     

硅太阳电池工程用数学模型参数的优化设计

根据硅太阳电池工程用数学模型,利用matlab/simulink模块建立了硅太阳电池阵列仿真模型.根据太阳电池组件仿真结果和实际测量结果的比较,分析了硅太阳电池工程用数学模型系数对仿真模型的输出特性精度的影响,并提出了不同太阳辐射强度时硅太阳电池工程用数学模型中系数b的优化设计计算公式.仿真结果表明,利用优化设计计算的参数可提高太阳电池阵列仿真模型的输出特性精度.     

多晶硅太阳电池绒面和二次扩散吸杂工艺研究

对100mm×100mm p型多晶硅片,采用单晶的绒面腐蚀工艺以及二次扩散吸杂工艺后,电池的电性能普遍有所提高.光电转换效率在批量工业生产中达11%左右,最高达到12%.比常规工艺转换效率增加10%左右.电池片的扩散长度L_D有明显提高.     

曲面硅太阳电池制备及性能分析

随着太阳电池的广泛应用,制备曲面硅太阳电池组件成为目前的一种应用趋势.但由于硅材料的机械性能使得其对于曲面电池组件制作存在困难,且效率较低.提出了一种任意曲面硅太阳电池组件制作方法,并通过太阳电池表面加装减反射软膜来提高其性能.实验测试曲面硅太阳电池的结果,显示其开路电压为1.945 V,短路电流为2.478 A,性能...     

Numerical modeling of loss mechanisms resulting from non‐uniform illumination in multijunction concentrator solar cells

Quasi‐3D distributed emitter models utilizing a unit cell‐based methodology have been successfully applied to the analysis of lateral current flow in solar cell emitter layers. However, the analysis of the specific loss mechanisms resulting from this flow has not been given adequate attention. In this work, a quasi‐3D model for the simulation of effects related to the lateral flow of current in a solar cell emitter layer, particularly under non‐uniform illumination, is developed. The model is applied to a specific case in which a GaInP/GaAs‐like two‐terminal solar cell is illuminated with a Lorentzian irradiance pattern, which is the expected pattern for parabolic trough concentrator. It is shown that bias‐point loss, which results from the variation in the local operating condition of the cell, is significant under highly non‐uniform illumination at low–moderate optical concentration. Understanding this loss mechanism is useful in considering trade‐offs related to the design of the optical concentrator system, as well as, the design of a grid electrode pattern for maximum power output. Copyright © 2013 John Wiley & Sons, Ltd.     

非晶硅太阳电池作为空间能源的性能特点

总结了非晶硅太阳电池在器件物理、制造工艺、大规模生产和应用方面所取得的重大进展。文章分析了非晶硅太阳电池作为空间能源系统技术上的主要优势;很高的质量比功率和可弯曲特性;极好的抗辐照性能;良好的高温性能;较高的空间效率和低的制造成本,这是其它太阳电池不具有的优势,使得非晶硅太阳电池能源系统在低成本通信卫星、平流层气球通讯平台,以及空间太阳能电站应用领域内具有较强的竞争力。     

多晶硅太阳电池光电转换效率模拟分析及验证

建立了一个可用于冶金法多晶硅太阳电池的一维模型,基于模型计算分析了晶粒尺寸和晶界复合速率对太阳电池光电转换效率的影响。在实验室实际制备了物理冶金法多晶硅电池,测试结果验证了仿真结果的有效性。研究结果表明,当晶粒尺寸大于5 mm时,电池的光电转换效率较高,在晶界复合速率较低的情况下,可以适当放宽对晶粒尺寸的要求。     

太阳电池用Bragg反射器的设计及研究

为提高GaAs/Ge太阳电池对光的吸收 ,我们对Ge衬底Bragg反射器进行了研究。根据GaAs材料对太阳光谱的吸收特点 ,通过转移矩阵的方法 ,对中心波长为 85 0nm的AlxGa1-xAs系材料Bragg反射器进行了光反射的理论计算和设计。依据理论设计 ,利用低压金属有机化合物化学气相沉积 (LP MOCVD)技术在Ge衬底上外延生长中心波长为 85 0nm的Bragg结构 ,测得的反射谱与理论设计相吻合 ,X Ray双晶衍射测得的Bragg周期厚度为 1 1 0nm。制作出具有埋层Bragg结构的GaAs/Ge太阳电池。对整个电池吸收系数的测试结果表明具有埋层Bragg结构的太阳电池的吸收系数低于无Bragg结构的电池。AM 1 .5光谱下电池I V曲线测试结果为 :Voc=1 .0 33V ,Jsc=2 6 .0 4mA/cm2 ,FF =82 .5 2 % ,η =2 2 .2 % ,对电池性能作了初步研究     

DIgSILENT与MATLAB接口的仿真建模

为充分利用电力系统仿真软件DIgSILENT开放性良好与数学模型软件包MATLAB数据处理能力强的优点,对DIgSILENT与MATLAB之间的接口技术进行了研究。在DIgSILENT中搭建调用接口模型并编写M文件来调用MATLAB的mdl控制模型,以实现联合仿真的目的。仿真结果表明调用方法有效、正确,弥补了DIgSILENT环境下不易实现宠大数据处理的缺陷。     

A novel and simple model for estimating the hourly global solar radiation

This letter proposes a novel and simple method for estimating solar radiation, named the ‘three‐point method’. The three points used to form the model are sunrise, sunset, and the maximum radiation point. The issue of obtaining maximum radiation is performed with the weighting evaluation of the HOTTEL and ASHRAE models. The feasibility and effectiveness of the proposed model is shown by simulation results. This model is equally applicable in any part of the world with a reassessment of the weighting factors for the maximum radiation. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

太阳能电池按经纬和时间自跟踪控制器设计

为使太阳能电池板保持与太阳光线垂直,以便提高太阳能电池的光电转换效率,设计了基于经纬和时间控制的太阳能电池板自动跟踪控制系统。采用2级控制方式,即利用高度/方位角全跟踪方式进行粗调、利用光照传感器进行细调。由PC计算出当前太阳位置,并将控制信息通过无线装置发送到现场,现场装置以PC计算的数据作为参考,控制步进电机改变电池板的方向,再通过光照传感器对电池板进行进一步的校正,使太阳能电池板始终保持与太阳光线垂直。通过实验分析,这种自动跟踪式电池板比固定式电池板对太阳能的吸收率可提高49.10%,有助于进一步提高能源的利用率。     

Sampled‐data poles,zeros, and modeling for current‐mode control

Exact and approximate sampled‐data models in closed forms are derived for switching DC–DC converters under peak/valley current‐mode control. The corresponding sampled‐data poles and zeros in closed forms are also derived. The location and stability conditions of the poles and zeros, boundary conditions of subharmonic instability, and nulling of the audio‐susceptibility are also derived. It is proved that the stable operating range of the source voltage is linearly proportional to the ramp slope. The sampled‐data models agree with previous experiment results and accurately predict the subharmonic instability. The different view from the sampled‐data model about the number and stability (minimum phase) of pole and zero does not necessarily invalidate the traditional continuous‐time averaged model. However, this different view gives better prediction about converter dynamics and is useful for the analog or digital controller design for DC–DC converters. Copyright © 2011 John Wiley & Sons, Ltd.     

The hyperpolarization‐activated current regulates synchronization of gap–junction‐coupled dopaminergic neurons in the midbrain—a combined approach between computational modeling and electrophysiological recording

To examine the functional role of hyperpolarization‐activated and cyclic nucleotide‐gated (HCN) current observed in mesencephalic dopaminergic neurons, we constructed a conductance‐based model that can mimic the electrical properties obtained in electrophysiological recordings of rat brain slices. In the model, blocking the HCN current resulted in a reduction of spontaneous firing rate and a change in the properties of autonomous pacemaking. In addition, reduced one‐dimensional phase equations and their coupled oscillators were analyzed. The analysis indicated that HCN channels can regulate the extent of synchronization of coupled dopaminergic neurons through gap–junction connections. Thus, the HCN current can effectively shape the autonomous and cooperative firing of dopaminergic neurons in the midbrain. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Simple and accurate approaches to implement the complex trans‐conductance suited for time‐domain simulators for small‐signal and large‐signal table‐based models

This paper focuses on the implementation of table‐based models of high‐frequency transistors for time‐domain simulators at microwave and mm‐wave frequencies. In this frequency range, the channel is not capable of responding to the excitation instantaneously therefore, a delay‐time exists between the channel response and the channel excitation. This delay is represented by a complex trans‐conductance in terms of circuit elements. The high‐frequency models of transistors are required to have the implementation of complex trans‐conductance, where the complex part accounts mathematically for the delay‐time between the channel response and the channel excitation. This paper presents simple and accurate approaches to incorporate the complex trans‐conductance in both small‐signal and large‐signal table‐based models for time‐domain simulators (MOS‐AK International Meeting. Eindhoven, Netherlands, April 2008). Implementation approach for each model, small‐signal and large‐signal, is presented in separated sections. In the first step, the delay is realized by the introduction of an ideal transmission line between the channel excitation and the channel response. As transmission lines are not generally suitable for time‐domain simulations, a lumped element equivalent network is introduced in the second step. The latter approach is fully compatible with time‐domain simulators but frequency limitation, determined by the delay‐time value itself, is introduced. Then the implementation of the complex trans‐conductance in large‐signal model is introduced. In terms of large‐signal behavior, delay‐time is important to achieve a non‐quasi static model. Yet again there is limitation in terms of the frequency range that is determined by the delay value itself. The methodology is illustrated on the small‐signal and the large‐signal equivalent circuit of a Multi‐Fin MOSFET transistor. Simulations are carried out by Cadence Spectre and Agilent ADS simulators, and comparisons are carried out between the simulation results and the measurements. Copyright © 2010 John Wiley & Sons, Ltd.     

Dynamic joint model of capacitive charge pumps and on‐chip photovoltaic cells for CMOS micro‐energy harvesting

On‐chip energy harvesting by means of integrated photovoltaic cells in standard CMOS technology can be successfully used to recharge or power‐up integrated circuits with the use of charge pumps for voltage boosting. In this paper, a tool to facilitate the design of such structures is proposed consisting of an accurate model of the joint dynamics of the micro‐photovoltaic cell and a capacitive DC/DC converter in the slow‐switching limit regime. The model takes into account both the top and bottom parasitic capacitances of the flying capacitors. We assume a classical model for the photodiode whose photogenerated current is extracted from device‐level simulations. The joint model is verified by circuit‐level simulations achieving high accuracy and computation time savings of up to 1700×. The joint model shows that the voltage generated by an integrated photovoltaic cell connected to a capacitive DC/DC converter is not constant even under constant illumination. This phenomenon can only be reproduced through the joint model and failing to take it into account results in an error in the estimation of the time needed by the DC/DC converter to reach a given output voltage. We also demonstrate that the maximum output voltage reached by a DC/DC converter in the slow‐switching limit regime when a photovoltaic cell is used as energy transducer depends on the switching frequency. Finally, the applicability of the model is illustrated through the optimization of time response and charge efficiency for the Dickson, Fibonacci, and exponential topologies in the case of implantable devices. Copyright © 2016 John Wiley & Sons, Ltd.     

A method for designing the power and capacitance of fuel cells and electric double‐layer capacitors of hybrid railway vehicles

A hybrid railway traction system with fuel cells (FC) and electric double‐layer capacitors (EDLC) is discussed in this paper. This system can save FC costs and absorb regenerative energy. A method for designing FC and EDLC on the basis of the output power and capacitance, respectively, has not been reported, although their design is one of the most important technical issues encountered in the design of hybrid railway vehicles. Such a design method is presented along with a train load pro?le and an energy management strategy. The design results obtained using the proposed method are veri?ed by performing numerical simulations for a running train. These results reveal that the proposed method for designing the EDLC and FC on the basis of the capacitance and power, respectively, and using a method for controlling the EDLC voltage, is su?ciently e?ective in designing e?cient EDLC and FC of hybrid railway traction systems. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(3): 47–54, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22395