微晶硅/晶体硅HIT结构异质结太阳电池的模拟计算与分析

Simulation and Analysis of μc-Si:H/CZ-Si Heterojunction Hit Solar Cells

运用AFORS-HET程序模拟分析μc-Si(p)/μc-Si(i)/c-Si(n)HIT结构异质结太阳电池的光伏特性,并研究发射层厚度、本征层厚度、本征层能隙宽度、界面态密度以及能带失配等参数对太阳能电池光伏特性的影响.计算结果表明:插入5 nm较薄微晶硅本征层,电池的转换效率最佳;随着微晶硅本征层厚度增加,电池性能降低,电池的界面缺陷态显著影响电池的开路电压和填充因子.对能带补偿情况进行模拟分析,结果显示,随着价带补偿(ΔEV)的增大,由界面态所带来的电池性能的降低逐渐被消除,当ΔEV=0.25eV时,界面态带来的影响几乎完全消除.通过优化各参数,获得微晶硅/晶体硅HIT结构异质结太阳能电池的最佳转换效率为19.86%.

The performances of μc-Si（p）/μc-Si（i）/c-Si（n） heterojunction solar cell were simulated by the AFORS-HET software. We studied the influence of the emitter layer, the intrinsic layer, the interface defect densities,the band gap and the bandgap offset, etc. , on the optoeleetrie characteristics of the solar cells. The results showed that the performances of solar cells were optimum as inserting an intrinsic layer of 5 nm,changed bad with increasing of the thickness. The interface states had remarkable influence on the open circuit voltages and fill factors. The effect of bandgap offset on the performances of solar cell has also been analyzed. With increasing of valence band offset （ΔEV）, the performances degradation of solar cells owing to interface states were recovered. When ΔEV reaches 0.25 eV, the influence of interface states was almost eliminated. By optimizing of the parameters, 19.86% of a conversion efficiency has been achieved.