高效GaAs/Si叠层电池设计优化

Abstract

模拟一种高效gAAS/SI两结叠层电池结构,将硅材料作为叠层电池的一个底电池利用起来,拓展光谱吸收.分别讨论了隧穿结和子电池对叠层电池的影响,结果表明薄的gAAS隧穿结可以获得高效率的叠层电池,1.05μM厚的顶电池基区是子电池电流匹配的最优条件,厚的底电池有助于叠层电池效率的提高.优化后的叠层电池在一个太阳,AM 1.5g光照条件下,效率可达到43.86%,其相应的开路电压VOC=1.76V,短路电流密度JSC=28.64MA/CM2,填充因子ff=87.25%,该设计为硅基高效太阳能电池的制备提供理论参考.

A structure of high-efficiency GaAs/Si two-junction tandem solar cell is simulated,which expand the spectrum absorption.The effect of the tunnel junction and subcells on the tandem solar cell is discussed respectively.It is shown that high-efficiency tandem solar cell can be achieved with thin GaAs tunnel junction.The optimal point for current matching between subcells seems to be for base layer thickness of the top cell equal to 1.05 μm.Thick bottom cell contribute to the enhancement of the efficiency of the tandem solar cell.Under 1 sun,air mass 1.5 G illumination,a tandem solar cell with an efficiency of 43.86% have been achieved after optimization,with the open circuit voltage(Voc) of 1.76 V,short circuit current(Jsc) of 28.64 mA/cm2 and fill factor(FF) of 87.25%,which provide theoretical reference to the preparation of high-efficiency silicon based solar cells.