Generalized analysis of bifacial solar cell design: Effective modelling using PC1D

Diffused bifacial silicon-based solar cells are one of the most promising PV technologies in the immediate future. A numerical analysis of critical parameters involved in bifacial devices by PC1D software is presented. n+pp+ and p+nn+ structures of surface-passivated bifacial devices are considered. Bifaciality is recognized as an important factor of device performance. The emitter profiles and grid design are co-optimized considering resistive and recombination losses. It is found that emitter profiles can be varied in the range of 60-120 Ω/□ of sheet resistance, to obtain high efficiencies. In addition, it is observed that the rear irradiation does not have a significant influence on the grid design. For a given bulk lifetime, reducing the wafer thickness results in a higher bifaciality. We also observe that p-type wafers can achieve a higher bifaciality than n-type counterparts. However, at high bulk lifetimes, the wafer type has a negligible influence. Finally, a detailed analysis of resistive losses and recombination is carried out, whereby the emitters are identified as primary contributors.