Analysis of the impact of rear side geometry on performance of back-contact back-junction solar cells

In this work, we performed a study of rear side geometry of a back-contact back-junction solar cell parameters: the emitter, the back surface field (BSF) and their gap distance by exploiting two-dimensional TCAD numerical simulations. All figures of merit have been considered in order to understand the impact of the dominant ones. Higher efficiency are lead by higher emitter width/pitch ratios, lower pitches, and minimum BSF and gap widths. The impact of emitter is explained in terms of lower recombination in bulk due to a larger p-n junction, the impact of BSF and gap dimensions are explained in terms of surface recombination losses at back interface and the impact of pitch in terms of higher series resistance.