FDTD优化a-Si∶H薄膜太阳电池Si_3N_4纳米柱陷光结构（英文）

Si_3N_4 Nanodiscs for Light Trappingin a-Si∶H Thin Film Solar Cells Optimized bythe FDTD

采用有限时域分析法研究了采用电介质Si3N4纳米柱为氢化非晶硅薄膜太阳电池的陷光结构时，其光吸收增强的情况。实验结果表明，电介质Si3N4纳米柱为氢化非晶硅薄膜太阳电池的陷光结构时，不仅可以增加吸收率和加宽吸收谱范围，而且在短波长范围内的吸收高于金属纳米颗粒。对于80nm和100nm厚的氢化非晶硅薄膜太阳电池，当达到最大吸收增强比1．60和1．53时，对应的电介质Si3N4纳米柱高度分别为90和95nm。当Si3N4纳米柱的直径D：160nm，间距P=240nm，高度H=90nm，而氢化非晶硅薄膜太阳电池的厚度在70-120nm变化时，吸收增强比在厚度为100nm时达到最大值1．60。总之，可以通过优化Si3N4纳米柱的尺寸来提高电池的转换效率。

The light absorption enhancement of the hydrogenated amorphous silicon thin film solar cell with dielectric Si3N4 nanodiscs as the light trapping structure was investigated by using the finite difference time domain(FDTD)method.The experimental results show that with the dielectric Si3N4 nanodiscs as the light trapping structure of the hydrogenated amorphous silicon thin film solar cells,the absorption rate can be increased and the absorption spectrum range can be broaden,and the light absorption is higer than that of metallic nanoparticles in the short wavelength region.For the hydrogenated amorphous silicon film solar cells with the thicknesses of 80 and 100 nm,when the maximum absorption enhancement ratios reach1.60 and 1.53,the related heights of the dielectric Si3N4 nanodiscs are 90 and 95 nm,respectively.When the diameter D,period Pand height Hof Si3N4 nanodiscs are 160,240 and90 nm,respectively,and the thickness of the hydrogenated amorphous silicon thin film solar cell changes from70 nm to 120 nm,the absorption enhancement ratio reaches the maximum of 1.60 with the thickness of 100 nm.In a word,the conversion efficiency of the hydrogenated amorphous silicon thin film solar cells can be improved by optimizing the size of Si3N4 nanodiscs.