Influence of surface structure on the performance of mono-like Si PERC solar cell

Mono-like Si wafers were textured by both alkaline solution and metal-assisted chemical etching (MACE) process. The influences of surface textures on the diffusion process, surface passivation, electrical property and performance of solar cells were investigated. The results show that the pyramid-like structures obtained by alkaline texturing facilitates a higher surface doping concentration, larger junction depth after diffusion and better passivation effect, compared with the honeycomb-like structures generated by MACE texturing. In the same wafer textured by alkaline solution or MACE, the mono-crystalline region exhibits a higher quantum efficiency than the multi-crystalline region. By combining the MACE and alkaline texturing processes, the honeycomb- and pyramid-like structures were generated on the surface of mono-like Si wafer, resulting in a conversion efficiency of 21.39% that is higher than that of the individually MACE or alkaline-textured solar cells by 0.4% and 0.02%, respectively.