A subtle modification of the device surface is able to reduce optical loss and to further achieve high photoelectric conversion efficiency for thin film solar cells. This work shows the manipulation properties of subwavelength periodic structures on incident light at air/glass surface. In order to explore the mechanisms of optical loss, the spectral response and energy distribution of light are investigated by using rigorous coupled wave analysis and finite difference time domain methods. Calculation results show that the diffraction scattering and gradient refraction index play a significant role for better photon harvesting. With an optimized design of [Formula: see text][Formula: see text]nm, [Formula: see text], and hemispherical shape structure, obvious improvement in transmittance, external quantum efficiency and photo-generated current is achieved. The photoelectric conversion efficiencies of amorphous silicon thin film cells with an absorbing layer thickness of 400[Formula: see text]nm is 8.04%, improved by 5.9% compared with the flat cell of equivalent size.

中文翻译：

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亚波长周期结构设计及其在薄膜太阳能电池光子控制中的作用

器件表面的细微修改能够减少光学损耗并进一步实现薄膜太阳能电池的高光电转换效率。这项工作显示了亚波长周期性结构对空气/玻璃表面入射光的操纵特性。为了探索光损耗的机制，利用严格的耦合波分析和有限差分时域方法研究了光的光谱响应和能量分布。计算结果表明，衍射散射和梯度折射率对更好的光子捕获起着重要作用。[公式：见文][公式：见文]nm、[公式：见文]优化设计，半球形结构，透光率明显提升，实现了外部量子效率和光生电流。吸收层厚度为400[公式：见正文]nm的非晶硅薄膜电池的光电转换效率为8.04%，与同等尺寸的平板电池相比，提高了5.9%。