晶体硅太阳电池的双层结构钝化膜研究

Research on Dual-Layer Passivation Films of the Crystalline Silicon Solar Cell

针对目前基于p型硅片制备的单结太阳电池进一步提高表面钝化膜生产效率,利用氮化硅(SiNx)薄膜良好的钝化效果与价格低廉的二氧化钛(TiO2)膜,降低SiNx镀膜厚度减薄对少子寿命的影响。在单晶硅片表面先用PECVD法沉积SiNx薄膜,然后用热喷涂沉积TiO2薄膜。对比测试了热喷涂沉积TiO2薄膜前后电池的性能,结果表明在SiNx膜上增加TiO2膜层后少子寿命明显提高,这可能是TiO2膜结构内存在固定正电荷所致。这种双层结构封装后的太阳电池显示出了较好的光学与电学性能,对进一步改进太阳电池性能具有重要参考价值。

The further improvement for the productivity of the surface passivation coating was investigated in single-junction solar cells based on p-type crystalline silicon wafers. The good passivation effect of silicon nitride （SiNx） and cheap titanium dioxide （TiO2） film were considered to reduce the thickness influence of SiNx film on the minority carrier lifetime. The SiNx film was firstly deposited on the surface of the monocrystalline silicon using the PECVD process, and then TiO2 was deposited using the thermal spraying process. The performances of solar cells before and after the thermal spraying deposition of the TiO2 film were compared. It is found that the minority carrier lifetime enhances obviously after adding the TiO2 film on the SiNx film, the reasonable explanation may be that the fixed positive charges exist in the TiO2 film. The optical and electrical properties of the encapsulated solar cells using the double-layer structure were improved. The results provide an important reference for further improving the performance of solar cells.