薄膜光伏组件在不同光谱分布下的测试差异

本文测试了非晶硅、碲化镉、铜铟镓硒和钙钛矿四种薄膜光伏组件的光谱响应曲线,选择单晶硅电池作为参考电池的光谱响应,利用两种太阳模拟器的光谱分布计算它们在不同光谱分布下的光谱失配情况,对比了不同光谱分布对这四种薄膜光伏组件测试结果的影响,从光谱失配角度给出了减小薄膜光伏组件测试误差的建议。     

分光谱太阳能光电转换系统研究

单种类光电子器件的光电响应特性难以获得与太阳能全光谱匹配的高效率光电转换,突破其物理限制的努力方向是研制高转换效率的“第三代”分光谱多结电池。在本工作中,采用分光谱技术,将太阳光谱分成4个子光谱区,分别为400－630nm;630－800nm;800-900nm;900-1800nm;与这些子光谱区的范围相对应,分别采用能隙值与子光谱区相匹配的4个不同种类的具有较高光电转换效率的高性能单结光电器件,实现将太阳光高效率转换成电能。在太阳能电池辐照测试的0.5－6.0个SUN(AM1.5G)变化条件下,对多光谱组合的太阳能电池的光电转换效率进行了测试,获得了在2.8个SUN(AM1.5G)辐照条件下37.7％的实测光电转换效率。在此基础上,给出了利用单结电池组合制备高效率组合型分光谱太阳能光电转换系统的途径,具有较低成本和实际推广应用价值。     

基于轨道参数算法的全天候室内太阳模拟器的研究

针对太阳能利用技术中,动态和准确模拟太阳光照的问题,研制了一种基于轨道参数的全天候室内太阳模拟装置。根据静态的太阳轨迹数据,实时进行装置灯光的模拟运行,并在运行中,实时检测灯照与太阳光的近似度。实验结果表明,此模拟装置的氙灯光源光谱分布在经过失配误差处理后波长能够满足GBPT12637-90中A级要求,模拟器的辐照度范围为0~1 600W/m2,平均辐照度为1 000W/m2,照度范围为0~65 000lux,有效辐照面积为400cm2,动态模拟偏差为4.3%。此装置基本实现了太阳光照的全天候模拟,对太阳模拟技术的发展有一定的借鉴意义。     

锥型亚波长光栅在薄膜晶硅电池中的吸收增强效应分析

基于严格耦合波理论,从反射率、吸收增强因子、光生载流子几率和理想光电转换效率几个方面模拟分析了不同锥型亚波长光栅对1μm厚晶硅电池产生的影响。模拟结果得出:在相同光栅高度下,虽然小周期(P=100nm)锥形亚波长光栅的表面反射率低于大周期(P=500nm)结构的表面反射率,但是大周期锥形亚波长光栅薄膜晶硅电池的光生载流子几率和理想光电转换效率高于小周期结构的相应值,且这种区别随着光栅高度增加而增加。在AM1.5D太阳光谱下,最优化的大周期光栅使得薄膜晶硅电池光生载流子几率和理想效率增加1.4倍和1.65倍,而最优化的小周期光栅只能分别增加0.54倍和0.48倍。     

In0.68Ga0.32As热光伏电池的制作和特性分析

用在InP衬底上失配生长的能隙为0.6eV的In0.68Ga0.32As制成了热光伏(TPV)电池。对其光伏特性的测试分析表明,通过对As组分渐变的InAsxP1-x缓冲层厚度的优化,可以将晶格失配引起的位错完全弛豫在缓冲层内,从而大幅改善热光伏电池的性能。在AM1.5G标准光谱下,与晶格失配没有被完全弛豫的热光伏电池相比,优化措施可将开路电压从0.19V提高到0.21V,外量子效率在长波处可达到85%,转换效率也提高了30%。     

太阳电池在不同光谱分布太阳模拟器下的性能差异分析

测试了单晶和多晶硅太阳电池的光谱响应曲线,将单晶硅光谱响应作为标准电池的光谱响应,利用BBA太阳模拟器和AAA太阳模拟器的光谱计算了多晶硅太阳电池在两种模拟器下的光谱失配因子,对在两种模拟器下测试结果的可靠性进行了分析。     

大光斑高均匀度发散式太阳模拟器设计

为了实现大光斑直径高均匀度太阳辐照模拟,设计了大光斑发散式太阳模拟器。根据太阳光谱分布特性选取短弧氙灯作为光源,建立光源功率计算模型;基于成像倍率和氙弧峰值点离焦量之间的关系,优化设计聚光系统和光学积分器,提高太阳模拟器的辐照均匀度;同时,结合短弧氙灯的光谱特性,建立光谱匹配模型,设计光学滤光片在不同波长的透过率。实验结果表明:设计的发散式太阳模拟器辐照面积为2 m,当工作距离为6、8、10 m时,辐照不均匀度分别优于3.33%、3.51%和4.3%,且光谱与AM1.5太阳光谱A级标准相匹配。     

太阳模拟器AM0型滤光片及其稳定性研究

太阳模拟器作为航天科技卫星空间环境模拟和太阳能电池检测与标定的必要模拟设备,越来越受到人们的关注。太阳模拟器滤光片作为模拟器的核心部件,通过对模拟器光源滤光,可以得到不同的太阳光谱辐照度。文中研究的AM0滤光片通过对氙灯光源滤光,可以得到大气层表面的太阳光谱辐照度分布。根据标准AM0光谱辐照度曲线和标准氙灯辐照度曲线,得到AM0滤光片透过率曲线。在此基础上对滤光片进行膜系设计和镀制,得到了满足国标A类标准的AM0滤光片。对滤光片进行了紫外辐照实验和高温烘烤实验,研究了其光学稳定性,所镀制的滤光片光学稳定性优于目前使用的滤光片。     

2.4m太阳模拟器设计

针对目标特性研究需求,设计了有效辐照面直径2.4 m的太阳模拟器。要求辐照面内的照度不小于0.3个太阳常数,出射光束准直角不大于1且被照面的不均匀度不大于3%,光谱失配误差达到Ｃ级。太阳模拟器主要由四个短弧氙灯、四个椭球面反射镜、两个平面反射镜、一组积分器和一个准直反射镜组成。对设计结果进行了软件仿真分析和实验测试。测试结果表明:太阳模拟器的有效光斑直径为2.43 m,被照面平均照度为3 382 lx,光束准直角0.97,不均匀度为2.8%,光谱失配误差达到Ｃ级,满足设计要求。     

光强和温度对多结太阳电池的影响研究

基于模拟太阳光源的方法,在室内研究了在不同光照强度、不同工作温度下GaAs多结太阳电池的输出特性.通过实验得出:随着光源辐照强度的增加,太阳电池的特性参数:短路电流Isc线性增加,开路电压Voc对数增加,最大输出功率P线性增加,光电转换效率η随聚光比增加到一定程度后减小.对比分析了光强和温度对电池输出特性的影响,数据结...     

Short‐circuit current of solar cells under artificial light

A model to estimate the short‐circuit current of a solar cell under artificial light from the short‐circuit current of the same solar cell under AM1.5 1 kW/m² is described. The results may help designers of solar‐powered portable equipment and consumer products working indoors or under a mixture of artificial and sunlight. It is concluded that the ratio of the short‐circuit currents of the same solar cell generated under fluorescent light of 1 lux illuminance divided by the short‐circuit current generated under standard 1 Sun AM1.5 conditions is around 3 × 10⁻⁶ for typical crystalline silicon and CIS solar cells. This value is one order of magnitude greater if the light source considered is an incandescent lamp. In the case of amorphous silicon solar cells the value of the ratio is close to 8 × 10⁻⁶ either for fluorescent or incandescent lamps. CdTe solar cells are also considered, and this factor is about 4 × 10⁻⁶ under fluorescent light, and four times bigger when an incandescent lamp is used. Some measurements performed validate the figures obtained. Copyright © 2002 John Wiley & Sons, Ltd.     

Uncertainty of the spectral mismatch correction factor in STC measurements on photovoltaic devices

Valuation of photovoltaic devices depends strongly on the measured power output of the device. This quantity is usually determined under artificial sunlight in production line measurement systems or industrial or research test labs. A practical calibration chain is realized essentially with measurements at solar simulators. The measurement conditions are defined in the IEC 60904 series of standards. An important part of the standard testing conditions is the definition of a specific spectral distribution of the sunlight (AM1.5 global). The inevitable deviations of the spectrum of artificial light sources from the standard spectrum have to be taken into account by a spectral mismatch factor. The uncertainty of this crucial correction is spectrally dependent, in most cases unknown and complex and inconvenient to evaluate. In this article a randomizing method is proposed which allows one to calculate the uncertainty of the mismatch factor from the uncertainties of the input parameters determined with high spectral resolution. Based on a range of different spectral responses of solar cells on the one hand and variations of the solar simulator spectral distribution on the other, we are able to generalize the results to a broad set of measurement configurations. A sensitivity analysis reveals the crucial wavelength regions and thus allows the systematic optimization of simulator spectra and selection of reference cells. Copyright © 2010 John Wiley & Sons, Ltd.     

Accurate Measurement and Characterization of Organic Solar Cells

Methods to accurately measure the current–voltage characteristics of organic solar cells under standard reporting conditions are presented. Four types of organic test cells and two types of silicon reference cells (unfiltered and with a KG5 color filter) are selected to calculate spectral‐mismatch factors for different test‐cell/reference‐cell combinations. The test devices include both polymer/fullerene‐based bulk‐heterojunction solar cells and small‐molecule‐based heterojunction solar cells. The spectral responsivities of test cells are measured as per American Society for Testing and Materials Standard E1021, and their dependence on light‐bias intensity is reported. The current–voltage curves are measured under 100 mW cm^–2 standard AM 1.5 G (AM: air mass) spectrum (International Electrotechnical Commission 69094‐1) generated from a source set with a reference cell and corrected for spectral error.     

Investigating the influence of the counter Si-cell on the optoelectronic performance of high-efficiency monolithically perovskites/silicon tandem cells under various optical sources

Nowadays, tandem structures have become a valuable competitor to conventional silicon solar cells, especially for perovskite over silicon, as metal halides surpassed Si with tunable bandgaps, high absorption coefficient, low deposition, and preparation costs. This led to a remarkable enhancement in the overall efficiency of the whole cell and its characteristics. Consequently, this expands the usage of photovoltaic technology in various fields of applications not only under conventional light source spectrum in outdoor areas, i.e., AM1.5G, but also under artificial light sources found indoors with broadband intensity values, such as Internet of things (IoTs) applications to name a few. We introduce a numerical model to analyze perovskite/Si tandem cells (PSSTCs) using both crystalline silicon (c-Si) and hydrogenated amorphous silicon (a-Si:H) experimentally validated as base cells. All proposed layers have been studied with J-V characteristics and energy band diagrams under AM1.5G by using SCAPS-1D software version 3.7.7. Thereupon, the proposed architectures were tested under various artificial lighting spectra. The proposed structures of Li4Ti5O12/CsPbCl3/MAPbBr3/CH3NH3PbI3/Si recorded a maximum power conversion efficiency (PCE) of 25.25% for c-Si and 17.02% for a-Si:H, with nearly 7% enhancement concerning the Si bare cell in both cases.     

Effects of spectrum on the power rating of amorphous silicon photovoltaic devices

The effects of different spectra on the laboratory based performance evaluation of amorphous silicon solar cells is investigated using an opto‐electrical model which was developed specifically for this purpose. The aim is to quantify uncertainties in the calibration process. Two main uncertainties arise from the differences in the test spectrum and the standard spectrum. First, the mismatch between reference cells and the measured device, which is shown to be voltage dependent in the case of amorphous silicon devices. Second, the fill factor of the device is affected by different spectra. Different cell structures and states (specifically different i‐layer thickness and levels of degradation) for the different light sources are investigated in this work. These sources are different solar simulators, LED sources, Tungsten as well as the standard terrestrial AM1.5G radiation. It is shown that the performance cannot be evaluated by short circuit current alone. The voltage dependent quantum efficiency of p‐i‐n devices can introduce a mismatch in the P_MPP of 1% for 250 nm i‐layer devices in as prepared state, rising to up to 4% for the 600 nm i‐layer devices at degraded state. Copyright © 2011 John Wiley & Sons, Ltd.     

Back amorphous‐crystalline silicon heterojunction (BACH) photovoltaic device with facile‐grown oxide ‐ PECVD SiNx passivation

This article reports on the integration of facile native oxide‐based passivation of crystalline silicon surfaces within the back amorphous‐crystalline silicon heterojunction solar cell concept. The new passivation scheme consists of 1‐nm thick native oxide and nominally 70‐nm thick PECVD silicon nitride. The low temperature passivation scheme provides uniform high quality surface passivation and low parasitic optical absorption. The interdigitated doped hydrogenated amorphous silicon layers were deposited on the rear side of the silicon wafer using the direct current saddle field PECVD technique. A systematic analysis of a series of back amorphous‐crystalline silicon heterojunction cells is carried out in order to examine the influence of the various cell parameters (interdigital gap, n‐doped region width, ratio of widths of p, and n‐doped regions) on cell performance. A photovoltaic conversion efficiency of 16.7 % is obtained for an untextured cell illuminated under AM 1.5 global spectrum (cell parameters: V_OC of 641 mV, J_SC of 33.7 mA‐cm ^{− 2} and fill factor of 77.3 %). Copyright © 2014 John Wiley & Sons, Ltd.     

Calibration of solar cells for space applications

The calibration of space solar cells can be performed under extraterrestrial conditions (in space) or Earth-bound (either in the laboratory or outdoors). The corresponding calibration procedures and correction methods to obtain the calibration value are described for measurements on a balloon or in a jet as well as in a solar simulator or under direct or global outdoor illumination. Special emphasis is given to bias and random errors that may influence the measurement uncertainty. For terrestrial calibration methods utilizing a spectral mismatch correction, an ambiguity in the calibration value arises due to differences between two well-known sources for the extraterrestrial spectral irradiance, as given by Thekaekara or the World Radiation Centre and to different estimates of the solar constant. Some calibration methods use light sources with spectra that are very different from the extraterrestrial spectrum. The impact of this on the size and error of the mismatch correction is quantized for all relevant cell technologies. As the mismatch correction depends both on calibration spectrum and cell spectral response, there is not a single terrestrial calibration method with best uncertainty for ‘all’ cell technologies. Rather, good control of measurement errors in spectral response and simulator spectrum measurement determine the applicability of the various calibration methods.©1997 John Wiley & Sons, Ltd.     

硅薄膜太阳电池抗反射微纳结构研究

在硅薄膜太阳电池中,灵活的光学设计可以实现表层的零反射损耗,增大吸收层中光的透射率,从而提高薄膜太阳电池的光收集能力。在薄膜太阳电池吸收层表面设计了矩形介质光栅。利用严格耦合波理论和模态传输理论研究了光栅结构参数对反射率的影响。考虑到AM1.5 G太阳能光谱和a-Si的吸收光谱,光栅参数进一步优化。由于微加工的误差,使得矩形光栅变成梯形光栅,必然会影响硅薄膜太阳电池表面反射率。研究结果表明,长周期光栅同样可以实现低反射率,在工艺上也容易实现。采用梯形光栅可进一步降低表面反射率,并且在太阳光入射角为-40°~+40°的范围内保持在6%以下。     

I—V Curve Characterization of n^＋／p／p^＋ Silicon Solar Cell

The analysis of solar cell performance has been done by simulating the external I-V characteristics of n^ /p/p^ single crystal silicon solar cell under high light intensity and 1.5 air mass(AM).This method allows the maximization of solar cell efficiency.To fabricate low-cost n^ /p/p^ single crystal silicon solar cells,solid source of doped phosphorous and boron was used.