太阳能电池用宽光谱减反射光栅的优化设计

Optimization of Wide Spectrum Anti-Reflective Grating for Solar Cell

为降低太阳能电池片表面的反射率，提出了一种基于SiO2/TiO2膜层的减反射光栅，该光栅由基底、浮雕结构和表面薄膜覆盖层组成。以加权平均反射率为评价函数，采用严格耦合波理论和遗传算法对光栅的槽深、周期、占空比、入射角和包覆层厚度等参数进行优化。所设计的太阳能电池用减反射光栅在入射波长为300~1100 nm，入射角度在±40°范围变化时加权平均反射率低于2.16%，最小加权平均反射率低于1.04%。数值分析表明设计的光栅具有优良的工艺容差。

An anti-reflective grating used for solar cell is proposed based on SiO2/TiO2 film to reduce its surface loss. It consists of substrate, relief structure and surface thin film. Rigorous coupled wave theory and genetic algorithm are employed to optimize the parameters such as groove depth, duty cycle, incident angle and thickness of surface thin film according to the merit function of the weighted average reflectivity. The optimized grating has the lower weighted average reflectivity than 2.16% with the incident wavelength from 300 nm to 1100 nm and the incident angle around ±40°. The lowest weighted average reflectivity is only 1.04%. Simulation results show sufficient manufacture tolerance of the designed grating.