In this study, we developed a novel method based on uniform and graded gratings on the front surface of ultra-thin film Si solar cells to enhance light absorption. The proposed gratings were designed in two configurations comprising penetration into the active layer and placement on it. These structures enhance absorption by scattering and diffracting light, and enlarging the optical path for photons. Simulations based on the finite element method and finite difference time domain technique showed that the graded gratings could significantly enhance absorption in the visible and infrared regions. The maximum current density and efficiency achieved for graded gratings placed on the top surface of the active layer were 21.7 mA/cm and 23.9%, respectively (47.6% and 48.4% higher compared with the reference cell).

中文翻译：

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使用渐变光栅增强超薄膜太阳能电池的光吸收

在这项研究中，我们开发了一种基于超薄膜硅太阳能电池前表面均匀渐变光栅来增强光吸收的新方法。所提出的光栅设计有两种配置，包括穿透有源层和放置在有源层上。这些结构通过散射和衍射光来增强吸收，并扩大光子的光路。基于有限元法和时域有限差分技术的仿真表明，渐变光栅可以显着增强可见光和红外区域的吸收。放置在有源层顶面上的分级光栅所实现的最大电流密度和效率分别为 21.7 mA/cm 和 23.9%（与参考电池相比分别高出 47.6% 和 48.4%）。