光伏电池组件太阳模拟器AM1.5滤光片的研究

通过将标准大气光谱与大功率圆弧形氙灯光谱的比较,获得了AM1.5型太阳能模拟器滤光片的透射率光谱曲线。通过膜系设计和镀制,研制出了中心波长为930 nm的负滤光片,该滤光片在930 nm处的透射率T=15%,400～750 nm波段内的平均透射率Ta≥93%,1200～1400 nm内平均透射率Ta≥91%。将6片相同的滤光片安装在测试面为1 200 mm×2 000 mm的脉冲式光伏组件太阳模拟器上进行测试,在氙灯的正上方,其光谱匹配度在0.91~1.05之间,达到了A类滤光片要求;而在离圆弧氙灯最远的位置2处,测试的光谱匹配度在0.73~1.06之间,达不到A类滤光片要求。最后,通过采用滤光片的优化组合拼接技术,使光伏电池组件模拟器测试面上所有点的光谱匹配度均达到了A类要求。     

大面积宽光谱太阳模拟器光谱匹配均匀度技术研究

针对IEC60904.9标准规定的光谱辐照度分布波长范围不能满足铜铟镓硒薄膜等宽光谱太阳电池伏安特性测试需求,提出了一种适用于工业生产用的大面积宽光谱太阳模拟器光机结构设计思路.依据IEC60904.3标准拓宽光谱波长范围为400～1 200 nm,并给出各光谱波段评判依据.详细介绍了宽光谱AM1.5G滤光片设计方法,并通过组合滤光片与单组滤光片进行比对试验,采用组合滤光片可使整体匹配偏差由9.4％缩小至5.4％.试验表明:采用组合滤光片可有效降低光源因角度效应造成大面积测试面光谱匹配不均匀的难题.     

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。     

Ge基底8～11.5μm长波通滤光膜的研制

论述了在Ge基底上镀制8～11.5 μm红外长波通滤光膜.通过对Ge基底和Ge、ZnS膜料的色散计算,优化膜系设计,进行工艺实验以及膜层的光学及耐环境实验,制备出满足应用条件的红外长波通滤光片,并已批量生产.     

渐变滤光铬膜的遮板设计与真空镀制

论述了在平面光学零件上镀制渐变滤光铬膜时,遮板的设计方法及其真空镀制工艺。它对非平面任何透过率曲线的渐变滤光膜的设计与镀制,亦有参考价值     

太阳紫外光谱辐射计的研制及丽江外场实验

为了实现对太阳直接光谱辐照度的地基观测,研制了一台用于测量太阳直射光谱辐照度绝对值的扫描式紫外光谱辐射计,工作波段250～400nm,通过太阳跟踪器及二维转台等设备实现地基观测时对太阳的自动跟踪.以NIST标准光源标定了这台光谱辐射计光谱辐照度响应度,定标误差2.4%.在云南丽江地区(26°52'N,100°13'E)开展的地面太阳直射紫外光谱辐照度观测试验进一步检验了仪器的性能.结果表明:时间、云量和大气气溶胶等因素对抵达地表的太阳直射紫外光谱辐照度有直接的影响.     

基于可调谐激光器的太阳光谱辐照度仪定标方法

太阳光谱辐照度仪是利用棱镜分光技术对太阳直射辐射进行连续光谱测量的新型仪器,为了实现高精度观测要求,开展了基于可调谐激光器的系统级定标方法研究。使用激光导入积分球产生的均匀辐照度场作为定标光源,利用标准辐照度探测器作为传递标准,将低温绝对辐射计的辐射标准传递到太阳光谱辐照度仪。在仪器的870 nm波段进行了定标实验,与标准灯法、Langley法得到的定标系数进行比对,偏差分别为2.84%和4.08%,验证了该方法的可行性。根据不确定度评估规范,这种定标方法的不确定度优于0.882%,可以用于高精度的太阳光谱辐射观测。     

动态光学目标模拟器的滤光片设计

光学成像敏感器是着陆器的重要组成部分,其性能的好坏直接影响着陆器的安全性。动态光学目标模拟器主要用于对光学成像敏感器的性能进行测试,由于光学成像敏感器接收的光谱条件苛刻,因此对动态光学目标模拟器也提出了很高的要求。本文对动态光学目标模拟器的出射光光谱特性进行了测量和分析,并设计了适当透过率的滤光片,保证了光学成像敏感器的功能实现。     

窄带负滤光片膜层的制备

介绍了光学产品用负滤光片的特点.负滤光片适用于镀制要求某一光谱范围高反射率、其他波段范围高透射的光学零件.讨论了窄带负滤光片膜层的结构特点、反射带宽度、反射率值与膜料及膜系的相对关系,给出了典型的理论光谱特性曲线.镀制出了接近理论光学特性的窄带负滤片膜层,膜层的中心波长定位精度2 nm,中心波长漂移不大于2 nm,非胶合状态下可直接在大气环境中使用.     

标准测试条件下人造太阳光源的谱失配及影响

标准测试条件下,人造太阳光源的光谱形式、辐 照强度、光谱失配因子等是影响太 阳电池器件测试结果准确性的重要因素。本文以标准太阳光谱AM1.5 为参考,从光谱失配角 度,计算和分析了4种常用人造太阳光源(Arc lamp灯、Q-Flash灯、Q-Flash W灯和ELH 灯)与标准太阳光谱AM1.5之间的光谱失配因子的变化和这四种人造 太阳光源辐照下晶硅电 池的输出参数的变化。计算结果表明:Arc lamp型人造太阳光源的光谱失配因子为 0.979, 晶硅电池输出参数最接近标准太阳光谱AM1.5辐照下的输出参数 ;因光谱失配影响,4种不同人造太阳光源辐照下晶硅电池的输出参数较标准太阳光谱AM1.5辐照下的输出 参数会发生明显变化。     

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.     

Spectral response and energy output of concentrator multijunction solar cells

The spectral response of concentrator multijunction solar cells has been measured over a temperature range of 25–75°C. These data are combined with reference spectra representing the AM1·5 standard as well as annual spectral irradiance at representative geographical locations. The results suggest that higher performance in the field may be obtained if multijunction cells are designed for an effective air mass higher than AM1·5. Copyright © 2008 John Wiley & Sons, Ltd.     

A self‐calibrating led‐based solar test platform

A compact platform for testing solar cells is presented. The light source comprises a multi‐wavelength high‐power LED (light emitting diode) array allowing the homogenous illumination of small laboratory solar cell devices (substrate size 50 × 25 mm) within the 390–940 nm wavelength range. The spectrum can be synthesized by independent tuning of the 18 different wavelengths to mimic AM1.5G as well as various indoor lamp spectra. The intensity can be controlled with a 2¹⁴‐bit accuracy and intensities up to 3 suns are possible with an approximate AM1.5G spectral distribution. For several wavelengths intensities up to 10 suns is possible, and for a few wavelengths up to 30 suns can be reached. The setup is equipped with reference diodes and an optical fibre coupling enabling calibration, monitoring and control of the light impinging on the sample. Through a computer controlled interface, it is possible to perform all the commonly employed measurements on the solar cell at very high speed without moving the sample. In particular, the LED‐based illumination system provides an alternative to light‐biased incident photon‐to‐current efficiency measurement to be performed which we demonstrate. Both top and bottom contact is possible and the atmosphere can be controlled around the sample during measurements. The setup was developed for the field of polymer and organic solar cells with particular emphasis on enabling different laboratories to perform measurements in the same manner and obtain a common basis for comparing data. The use of the platform is demonstrated using a standard P3HT:PCBM polymer solar cell but is generally applicable to any solar cell technology with a spectral response in the 390–950 nm region. Copyright © 2010 John Wiley & Sons, Ltd.     

Analytic computation of the photocurrent density in a n-6H-SiC/p-Si/n-Si/p-Si0.8Ge0.2 multilayer solar cell

In this work we conceived a model of a multilayer solar cell composed by four layers of opposite conductivities: an n-type 6H-SiC used as a frontal layer to absorb high energy photons (energy gap equals 2.9 eV), a p-type Si layer, an n-type Si layer and a p-type SiGe back layer to absorb low energy photons (Si_0.8Ge_0.2 with an energy gap equal to 0.8 eV). The impurity concentration in every layer of the model is taken equal to 10¹⁷ cm⁻³ to ensure abrupt junctions inside the cell. The optical properties of the separate layers have been fitted and tabulated to be used for thin films devices numerical simulation. We developed the equations giving the minority carrier concentration and the photocurrent density in each abscissa of the model. We used Matlab software to simulate and optimize the layers thicknesses to achieve the maximum photocurrent generated under AM0 solar spectrum. The results of simulation showed that the optimized structure could deliver, assuming 10⁵ cm/s surface recombination velocity, a photocurrent density of more than 53 mA/cm², which represents 88.3% of the ideal photocurrent (59.99 mA/cm²) that can be generated under AM0 solar spectrum.     

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。     

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.     

Progress in crystalline multijunction and thin-film photovoltaics

Photovoltaics are important in terrestrial applications such as remote power and renewable energy but are the primary source of electrical power for space systems. For space applications, priorities are high conversion efficiency and resistance to radiation-induced degradation. The emphasis is on III-V multijunction solar cells and comparatively lower efficiency but flexible, lightweight thin-film solar cells. Triple-junction III-V solar cells have reached conversion efficiencies of 30% at air mass zero (AM0). New lattice mismatch techniques and nitride materials hold promise for further efficiency increases. Thin-film solar cells generally have less than 15% efficiency but greater radiation resistance, lower cost, and lower mass.     

Progress in crystalline multijunction and thin-film photovoltaics

Photovoltaics are important in terrestrial applications such as remote power and renewable energy but are the primary source of electrical power for space systems. Here, priorities are high conversion efficiency and resistance to radiation-induced degradation and emphasis is on III-V multijunction solar cells and lower efficiency but flexible, lightweight thin-film solar cells. Triple junction III-V solar cells have reached conversion efficiencies of 30% at air mass zero (AM0). New lattice mismatch techniques and nitride materials hold promise for further efficiency increases. Thin-film solar cells generally have less than 15% efficiency but greater radiation resistance, lower cost, and lower mass.