太阳电池内部电阻对其输出特性影响的仿真

通过对太阳电池的等效电路进行分析,建立了太阳电池的计算机仿真模型,定量地模拟了在一定光照下太阳电池内部的等效并联电阻及串联电阻对其伏安特性、开路电压、短路电流及填充因子的影响的程度。仿真结果表明：等效并联电阻产生的漏电流会影响太阳电池的反向特性和正向小偏压特性,且并联电阻影响其开路电压,但对短路电流基本没有影响；等效串联电阻会影响太阳电池的正向伏安特性和短路电流,而对开路电压没有影响；另外,并联电阻的减小和串联电阻的增大都会使太阳电池的填充因子和光电转换效率降低。仿真结果与实际测量的数据取得了相一致的结论。     

石墨烯-硅肖特基结太阳电池的仿真研究

石墨烯-硅肖特基结太阳电池的开路电压、短路电流密度较低,其主要是受到本征石墨烯较小的功函数及较大的薄膜电阻的影响。针对这些问题,该文基于实验报道的石墨烯和晶硅电学参数,利用AFORS-HET软件对石墨烯-硅肖特基结太阳电池进行仿真模拟。模拟结果表明,石墨烯层中的受主浓度、功函数、及禁带宽度的增加都能提高开路电压。而晶硅层施主浓度的提升则会使开路电压下降,随着晶硅施主浓度的增加,开路电压从494.1 mV下降到386.6 mV。最后对晶硅及石墨烯层的厚度优化,电池效率达到11.92%,为目前报道此种结构电池的模拟最高值。     

太阳电池Ⅰ-Ⅴ测试仪校准实质的研究

测试分析了不同辐照、不同温度下太阳电池的短路电流、开路电压和功率的变化,比较了采用短路电流和功率校准后太阳电池电性能的测量结果,得到太阳电池Ⅰ-Ⅴ测试的校准实质.     

开路电压与太阳电池少子寿命关系的推导及其应用的研究

从理论上详细推导了晶体硅太阳电池在脉冲光照下,开路电压Voc(t)与少数载流子寿命的关系,同时研究了N-P结势垒电容放电时对Voc(t)的影响;从实验上验证了开路电压随时间的衰减关系,并运用该关系测量了硅太阳电池少数载流子寿命,测量结果较为准确.     

月尘对太阳电池阵开路电压影响研究

通过地面模拟实验获得月尘对光线遮挡效果数据,结合月尘和光传输特性,拟合出一新的月尘对光线遮挡数学模型。理论计算结果与实验数据进行对比,验证该模型的准确性。发现随着月尘厚度线性增加而光线的透过率呈指数下降。通过月尘吸附对太阳电池阵开路电压影响的研究,提出一个新的解析表达式。地面模拟实验获得月尘对太阳电池阵开路电压影响数据,理论计算结果与实验数据进行对比,验证该理论模型的可行性和准确性。发现随着月尘厚度线性增加太阳电池阵开路电压呈指数下降。     

测量方式对太阳电池输出性能测试的影响

通过对二线与四线接法测试单晶硅太阳电池I-V曲线的实验结果对比,分析串联内阻对于太阳电池短路电流、开路电压、填充因子及最大输出功率测量结果的影响.结果发现串联内阻越大,太阳电池的短路电流、填充因子及最大输出功率测量结果越小,但对开路电压基本无影响.且太阳电池接收光强越大即输出电流越大时,串联内阻的影响也越大.二线法因串...     

铝粉活性对双面PERC太阳电池铝浆性能的影响

探究了铝粉活性对铝浆电阻及双面PERC太阳电池开路电压的影响.实验结果表明:高活性的铝粉制备的铝浆具有较低的方阻、接触电阻及线电阻,且铝硅接触电阻率可低至11.5 mΩ?cm2;一定范围内,活性较低的铝粉制备的铝浆具有较高的开路电压,开路电压可达690.774 mV.根据太阳电池的尺寸、钝化膜质量、背面激光开槽面积、主...     

利用开路电压测量太阳电池外量子效率

首先利用太阳电池光照下的J-V特性,推导短路电流密度Jsc、开路电压Voc与光照面积和总面积的比值AΦ/AT之间的关系,分析利用短路电流密度测量外量子效率EQE(λ)SC的误差来源。并利用J-V特性将开路电压Voc表示的外量子效率EQE(λ)OC与常规利用短路电流密度Jsc表示的外量子效率EQE(λ)SC利用fEQE因子相关联。最后,测量不同面积晶体硅太阳电池的EQE(λ)OC、EQE(λ)SC并与PC1D模拟的EQE(λ)SCPC1D曲线进行对比,得到相应结论。该测试方法对提高太阳电池量子效率测试的准确性具有一定指导意义。     

CH3NH3PbI3形貌对钙钛矿电池性能的影响研究

研究不同CH_3NH_3bI_3钙钛矿形貌对钙钛矿太阳电池光伏性能的影响。采用传统的一步法和三步法制备出不同CH_3NH_3bI_3钙钛矿形貌对电池的光伏性能有重要影响。结果表明,钙钛矿在TiO+2电子传输材料表面的覆盖程度对钙钛矿太阳电池的开路电压和填充因子有重要影响。三步法制备的钙钛矿太阳电池获得1.03 V的开路电压和20.25 mA/cm~2短路电流密度,而一步法只有0.72 V和18.42 mA/cm~2。同时,三步法制备的钙钛矿太阳电池的填充因子高达77.2%,相比一步法只有64.5%。2种方法制备的钙钛矿电池分别获得17.36%和8.55%的光电转换效率。利用电化学阻抗谱进一步分析一步法和三步法制备的钙钛矿太阳电池的内部电荷复合动力学过程,解释三步法制备的钙钛矿太阳电池获得更高开路电压的原因。     

带有缓变层的大面积集成型a－Si：H太阳电池的研制

报道了把缓变层用于大面积（２７９０ｃｍ２）单结集成型ａ－Ｓｉ：Ｈ太阳电池板工业化生产的研究工作。分析了它对太阳电池板性能参数Ｖｏｃ、Ｉｓｃ、ＦＦ、η的影响和对提高ａ－Ｓｉ：Ｈ太阳电池板转换效率的作用。试验所得电池板的平均开路电压达２５．１Ｖ，平均转换效率达６．２％，分别比同时生产的无级变层电池板的水平提高９．１３％和１６．９８％。试验中最好的电池板开路电压达２５．６Ｖ，转换效率达６．６％。     

微晶硅材料和电池特性的相关研究

主要采用甚高频等离子体增强化学气相沉积技术制备了系列微晶硅材料和电池。通过对材料电学特性、结构特性和电池间性能关系的研究,获得了高效率微晶硅薄膜太阳电池所对应材料的基本特性:暗电导在10~(-8)s/cm量级上,光敏性大于1000,晶化率约50%。进行了制备电池的开路电压和表观带隙之间关系的研究。     

临近空间太阳电池模型修正与发电量预测研究

由于在飞行过程中,温度、辐照度和倾角变化都会对临近空间飞行器上太阳电池的输出功率及效率产生影响,该文利用太阳光模拟器及薄型晶体硅太阳电池,进行多组测量实验,得到在不同温度、辐照度和倾角条件下,太阳电池的短路电流、开路电压等参数,并通过与模型仿真结果进行对比,对已有太阳电池电模型进行修正,得到更接近真实飞行工况的临近空间飞行器用薄型晶体硅太阳电池的模型。最后,基于修正后的模型通过仿真对太阳电池阵列在临近空间的全天发电功率变化趋势进行预测,可为临近空间飞行器用太阳电池阵列设计与功率预测提供重要参考。     

Lateral current effects on the voltage distribution in the emitter of solar cells under concentrated sunlight

The design of the grid contact in silicon solar cells is one of the most important steps for the optimization and fabrication of these energy conversion devices. The voltage drop due to the lateral flow of current towards the grid fingers can be a limiting factor causing the reduction of conversion efficiency. For low current levels this voltage drop can be made small, for typical values of sheet resistance in the emitter, but for solar cells made to operate at high sun concentrations this efficiency loss can be important, unless there is a clear vision of the current and voltage distribution so that the emitter and grid design can be improved. Hence, it is important to establish and solve the current and voltage distribution equations for solar cells with a grid contact. In this work, first these equations are established and then they are solved in order to show the effects that the lateral current flow in the emitter cause on the voltage distribution, particularly at high illumination levels. In addition, it will be shown that the open circuit voltage is significantly reduced due to the lateral current flow as compared to the value predicted from a simple equivalent circuit with a lumped resistance model.     

微晶硅电池的制备及提高其效率的优化

采用甚高频等离子体增强化学气相沉积(VHF-PECVD)技术制备了不同硅烷浓度系列的微晶硅电池。结果表明:电池的开路电压随着硅烷浓度的增大而逐渐增加,而电池的短路电流则先增加后减小,在转折点电池的效率达到最大,填充因子则变化不明显;(220)择优取向出现,I(220)/I(111)比值大,电池的短路电流密度也大,电池的效率也最高;在实验的范围内,电池的短路电流密度和厚度成正比例关系;首次在国内制备出了效率达7.3%,短路电流密度(Jsc)为21.7mA/cm2,开路电压(Voc)为0.52V,填充因子(FF)为65%的微晶硅电池。     

Classification of shunting mechanisms in crystalline silicon solar cells

The efficiency of a solar cell is given by its average electrical parameters. On inhomogeneous materials and especially on large-area solar cells the inhomogeneity of the short circuit current, the open circuit voltage and the fill factor are important factors to reach high and stable efficiencies and may limit the overall performance of the device.A locally increased dark forward current (shunt) reduces the fill factor and the open circuit voltage of the whole cell. The inhomogeneity of the forward current in a solar cell can be measured using lock-in thermography. The quantitative and voltage-dependent evaluation of these thermographic investigations of various solar cell types on mono- or multi-crystalline silicon enables the classification of the different shunting mechanisms found. By further microscopic investigations the physical reasons for the increased dark forward currents can be determined.It turns out that a high density of crystallographic defects like dislocation tangles or microdefects can be responsible for an increased dark forward current. Unexpectedly, grain boundaries in solar cells on multicrystalline silicon do not show any measurable influence on the local dark forward current. In most cases shunts caused by process-induced defects are dominating the current–voltage characteristic at the maximum power point of the solar cell. In commercial solar cells shunts at the edges are most important, followed by shunts beyond the grid lines.     

晶体硅太阳电池选择性扩散的研究

该文主要介绍一种制造太阳电池的选择性扩散新工艺,采用印刷电极的方法在硅片上的电极位置印刷高 磷浆料,然后在整个硅片表面喷涂一层浓度较低的磷源,放入高温炉中扩散后形成电极下具有较高的表面掺杂浓 度(-1020／cm3),电极间具有相对较低的表面掺杂浓度(-1019／cm3)。这样在电极下及具附近将构成一个浓度差结。 这种发射极结构有利于减小发射区复合电流、提高短波响应、作好欧姆接触和提高太阳电池的开路电压等优点。     

High Concentration Silicon Solar Cells

The present state-of-the-art of silicon high concentration solar cells is reviewed. Two cell structures, the silicon point contact cell and the microgrooved cell structure, have demonstrated efficiencies of 28% at 150× and 24.7% at 100×, respectively. The problems associated with operation at high concentration are discussed. It is noted that Auger recombination is the limiting factor in the operation of high efficiency solar cells, affecting not only the open circuit voltage, but having a great impact on the short circuit current as well. With additional design improvements, efficiencies over 30% at concentration appear to be within reach.     

温度对多晶硅太阳电池性能影响的研究

对商业用冶金级和太阳能级多晶硅太阳电池不同温度下的性能参数做了分析,验证了太阳能级硅电池的性能优势。实验结果表明,随着温度T的升高,开路电压V_(oc),最大输出功率P_m,转换效率η近似线性下降,短路电流I_(sc)近似线性上升,填充因子FF的实验值和理论值变化趋势一致,当T40℃时,FF随T升高明显下降。对开路电压V_(oc)随温度T升高的线性下降速率dV_(oc)/dT进行定量分析。dI_(sc)/dT变化量与dV_(oc)/dT相比可以忽略。     

A simple analytical treatment of edge-illuminated VMJ silicon solar cells

The series connected silicon vertical multi-junctions (VMJs) solar cells have been suggested as means for ensuring high voltage high efficiency solar cells. This study includes a review of some previously published work concerning the edge-illuminated VMJs solar cells. We introduce a simple one-dimensional analysis to study the high voltage series connected silicon VMJs solar cells. The cell, under study, consists of 40 VMJs. Each junction (unit cell) has dimensions of 250 μm × 0.78 cm × 500 μm. We calculate the short circuit current, the open circuit voltage and the efficiency for an ideal cell, having perfect carrier collection at short circuit conditions, and for real cells. An optimization with respect to the base doping, the emitter doping, the surface recombination velocity and the number of junctions is done for the real cell. A conversion efficiency of 20% has been calculated under AM1.5 light spectrum for real cells having a base doping of 10¹⁶ cm⁻³ and an emitter doping of 10¹⁷ cm⁻³.     

Effect of temperature on dark current characteristics of silicon solar cells and diodes

The influence of temperature on the dark forward current–voltage characteristics of a single crystalline silicon solar cell and a small silicon diode within the range from 295–373 K has been analysed. It was shown that the forward voltage of the solar cell degrades 2 mV and in the case of diode 1 mV per 1 K temperature increases at constant forward current of 100 mA. Thermal resistance and heat transfer from the solar cell by using a thick copper plate as a heat sink have also been discussed. For the series resistance determination the current–voltage I–U characteristics of single crystalline silicon solar cells in different temperatures were measured in the dark. It was proved that series resistance of the silicon solar cells and diodes is temperature dependent and increases with temperature increase 0.65% K^?1. Therefore, protection of silicon solar cells as well as silicon diodes against overheating is essential during their exploitation. Copyright © 2005 John Wiley & Sons, Ltd.