ANovel Co-Diffusion Process for P-type PERL Solar Cells by Using Aluminum Doping Paste

Passivated emitter and rear locally diffused (PERL) cells may be an alternative to the market of highefficiency silicon-based solar cells. In this paper, we present a novel co-diffusion method for fabricating PERL cells. This method first locally prints aluminum doping paste and follows by a standard phosphorus diffusion for forming both front n+ and local rear p+. An efficiency gain of 0.08 % compared to the standard PERC cells was demonstrated by using this method. However, no improvement in open circuit voltage (V
_oc
) and short circuit current (I
_sc
) limited the efficiency of the PERL cells in this preliminary study. We confirmed that this limited Voc and Isc mainly caused by the rough surface in the regions of the printed lines. A solution to this rough surface issue is also given in this paper, indicating the efficiency of the PERL cells can be further improved by optimizing the process.