设计了一维双层余弦共形光栅结构的单晶硅薄膜太阳能电池.利用时域有限差分法模拟计算了双层余弦共形光栅结构和对照组结构的吸收光谱; 利用归一化光吸收密度的概念, 定量分析了300～700 nm和700～1 100 nm两个波段的光吸收效率.结果表明双层共形光栅结构具有更好的全波段吸收效率, 且在长波段余弦光栅比矩形光栅具有更好的光捕获和吸收作用.利用光吸收增强谱和电磁场强度分布图, 分析了余弦光栅在长波段的吸收增强机理.通过计算短路电流密度, 发现双层余弦共形光栅结构比平板结构太阳能电池的短路电流密度提高了79.5%, 余弦光栅结构比矩形光栅结构的短路电流密度提高了8.5%.

A structure of one-dimensional bilayer cosine conformal grating crystalline silicon thin film solar cell was designed. The absorption spectra of bilayer cosine conformal grating structure and contrast groups were simulated by using the finite difference time domain method ; The absorption efficiencies of two wavelength regions of 300 ~ 700 nm and 700 ~ 1100 nm were quantitatively analyzed by using the concept of normalized optical absorption density. It was found that bilayer conformal grating structure has better absorption efficiency in full wavelength band and cosine grating has better light trapping and absorbing than rectangular grating in long wavelength region. To analyze the mechanism of optical absorption enhancement, absorption enhancement spectra and distributions of electromagnetic field intensity were plotted. Through the calculation of short-circuit current density, it was found that the short-circuit current density of bilayer cosine conformal grating crystalline silicon thin film solar cell increased by 79.5% relative to planar structure, the short-circuit current density of cosine grating structure increased by 8.5% relative to rectangular grating structure.