薄膜太阳电池二元光栅结构

Study on Thin-film Solar Cells with Binary Grating

提出了采用二元光栅结构提高太阳能薄膜衍射效率的技术方法。利用对透射率函数的傅里叶变换计算出垂直入射时二元光栅的衍射光场分布。研究了不同阶次二元光栅在可见和近红外波段的衍射零级光强和总衍射效率随波长变化的规律。以硅基太阳能薄膜为例,分别计算了普通相位光栅和二阶、三阶二元光栅随波长零级光强的变化规律和衍射效率。结果表明,与普通相位光栅结构相比,二元光栅结构能够在较宽波段提高光衍射效率。

It is proposed to use binary grating to enhance the diffraction efficiency of thin-film solar cells.Diffraction field distributions of the binary gratings with vertical incidence were calculated by the Fourier transform of the grating transmission function,and the total diffraction efficiency of the difference binary grating was calculated within the wavelength of 0.4~1.3 μm.Taking thin-film silicon solar cells for example,the variations and diffraction efficiency of the general phase grating,two-step binary grating and three-step binary grating with the wavelength zero-order diffraction intensity were calculated,respectively.The results show that the total diffraction efficiency within wide wavelength bands can be enhanced greatly by adopting binary gratings structure compared with using general phase grating.