宽波长太阳能电池抗反射层结构设计

Design of a broadband anti-reflection coating for solar cells

为了降低太阳能电池表面对入射光的反射,提高其光电转换效率,设计了入射光谱在400～1100nm宽波长范围内的二维亚微米抗反射层结构。该结构主要由高折射率ZnS膜层、低折射率MgF2膜层及二维亚微米光栅层等组成。采用严格耦合波分析理论计算了此结构的反射特性,当ZnS膜层、MgF2膜层、光栅深度及光栅周期分别为50nm、150nm、200nm及400nm,入射角在0～80°变化时,其平均反射率为7.76%。计算结果表明:所设计的抗反射层结构可有效降低太阳能电池表面对入射光的反射,从而提高其光电转换效率。

Reflection of incident light from the surface of solar cells is one of the major mechanisms seriously affecting the photovoltaic transform efficiency of the solar cells. To reduce the reflection, a two dimensional submicron anti-reflection coating with the incident wavelength from 400 nm to 1 100 nm was designed.The designed structure was mainly composed of a ZnS film, an MgF2 film and a two dimensional submicron grating. The reflection efficiency of the structure was calculated by the rigorous coupled wave analysis theory. The average reflection efficiency of the designed anti-reflection coating was 7.76% when the incident angle varied from 0° to 80° with the height of the ZnS film, the MgF2 film, the depth and the pitch of the grating of 50 nm, 150 nm, 200 nm and 400 nm respectively. Results show that the designed anti-reflection coating can effectively reduce the reflection from the Si surface to improve the photovoltaic transform efficiency of the solar ceils.