Crystalline silicon solar cells selective emitter pattern design

Selective emitter in crystalline silicon solar cells improves the cell efficiency by reducing the recombination in the emitter region while maintaining low contact resistance to the front side electrodes. There are many approaches to realize selective emitter solar cells, some more complicated than the others, but all involve creating heavier doping in the region under electrodes. In this paper, we present the effect of selective emitter patterns, with or without heavy doping under busbars, on the solar cell performance. The results showed basically identical electrical characteristics for both types of patterns. Even though the selective emitter structure in this study was made with a printable dopant approach, the same results could apply to other selective emitter methods, including laser doping and ion implantation. This conclusion points to potentially significant savings in materials and/or processing time as heavy doping is needed only to cover the finger area but not the busbars.