Reduced recombination losses for PERC cell using a selective emitter structure formed by screen-printed resist masking combined with etch-back process

摘要

We present the improvement of the p-type passivated emitter and rear cell (PERC) with a selective emitter (SE) structure using screen-printed resist masking combined with wet chemical etch-back process. The structure of SE PERC solar cell is displayed in Fig. 1. The concept of an SE structure is based on removal of the highly doped layers (n~(++)) in the areas not intended for metallization. For p-type solar cells, the lightly doped emitter areas (n~+) obtained by the above mentioned process lead to a reduced Auger recombination and Shockley-Read-Hall (SRH) recombination, thereby improving the performance of PERCs. An n~+ emitter by etch-back process showing high sheet resistance (R_(sheet)) ensures a better blue response, resulting in high internal quantum efficiency.