为了研究Ag纳米线对单晶硅薄膜太阳能电池光吸收效率的影响, 设计了固定体积比例下具有三角形光栅和矩形光栅的单晶硅薄膜太阳能电池结构.在两种结构的Ag-Si交界处分别添加横向截面为圆形和矩形的Ag纳米线阵列, 利用有限时域差分法分别模拟计算了这两种结构的太阳能电池和对照组的吸收光谱.通过扫描优化得到两种光栅结构的最佳高度、纳米线横截面积以及分布密度, 并计算出最优条件下300~1 100 nm波段的光吸收效率.通过分析光吸收增强谱和电磁场强度分布图得出了含有纳米线模型在长波段的吸收增强机理.结果表明, 添加了Ag纳米线后的两种太阳能电池模型均比两种对照组模型具有更好的光捕获和吸收作用, 在矩形光栅模型中添加Ag纳米线后吸收效率的提升要比三角形光栅模型中更为明显.研究结果可为新型太阳能电池的结构参数设计提供参考.

In order to study the influence of Ag nanowires on the light absorption efficiency of crystalline silicon thin film solar cells, a kind of crystalline silicon thin film solar cell structure with triangular grating and rectangular grating at fixed volume ratio was designed. At the Ag-Si junction of the two structures, a circular and rectangular Ag nanowire array were added respectively. The absorption spectra of these two structures and the control group were simulated by finite difference time-domain method. The optimal height, nanowire cross-sectional area, and distribution density of the two grating structures were obtained by sweeps function of finite difference time-domain method software, and the light absorption efficiency of wavelength region of 300~1 100 nm was calculated under the optimal conditions. The absorption enhancement mechanism of the nanowire model in the long wavelength band was obtained by analyzing the light absorption enhancement spectra and the electromagnetic field intensity distribution. The results showed that the two structures with Ag nanowires had better light capture and absorption than the two control groups. Moreover, the absorption efficiency of Ag nanowires in the rectangular grating model is improved more significantly than the triangular grating model, which can provide reference for the design of structural parameters of new solar cells.