基于光栅结构的碲化镉太阳能电池吸收层设计

Structural Design of Absorption Layer in CdTe Solar Cells Based on Grating Structure

设计了一种吸收层为双填充比矩形光栅结构的碲化镉薄膜太阳能电池，利用时域有限差分法对矩形光栅和双填充比矩形光栅碲化镉吸收层在250～1000nm入射波长范围内的吸收效率进行分析．实验结果表明：相比于平板型吸收层，单填充比和双填充比矩形光栅结构的吸收效率均有较大提高；双填充比矩形光栅在整个可见光范围内的吸收率整体得到提高，其对可见光的平均吸收率相比于平板型至少提高10％．可见通过优化太阳能电池吸收层的结构，光子在光栅内的随机反射增加了光在吸收层的作用时间和距离，提高了薄膜太阳能电池的光电转换效率．

A thin-film solar cell with a grating of double filling ratios in the layer was designed. The structure of double filling ratios is to increase the absorption in the CdTe thin-film layer. By applying FDTD method, the absorption efficiency in the range of 250 - 1 000 nm has been analyzed for CdTe layer with rectangular and rectangular with double filling ratios grating. The results show that the absorption efficiency of the single filling ratio and double filling ratios grating structures can be improved relative to the fiat absorption layer. The average absorption rate of double filling ratios grating increased by at least 10% over non patterned in the range of almost all visible spectrum. The results indicate that, by designing the structure, random reflection photonic in grating increases the effect of time and distance in the light absorption layer, and finally improves the photo electric conversion efficiency of the thin-film solar cell.