Theoretical limiting-efficiency assessment on advanced crystalline silicon solar cells with Auger ideality factor and wafer thickness modifications

Abstract

With the improvement of surface passivation, bulk recombination is becoming an indispensable and decisive factor to assess the theoretical limiting efficiency ( ${\eta }_{\lim }$) of crystalline silicon (c-Si) solar cells. In simultaneous consideration of surface and bulk recombination, a modified model of ${\eta }_{\lim }$ evaluation is developed. Surface recombination is directly depicted with contact selectivity while bulk recombination is revised on the aspects of ideality factor and wafer thickness. The ${\eta }_{\lim }$ of the double-side silicon heterojunction (SHJ) and double-side tunneling-oxide passivating contact (TOPCon) solar cells are numerically simulated using the new model as 28.99% and 29.19%, respectively. However, the ${\eta }_{\lim }$ of single-side TOPCon solar cells, the more practicable scenario, is only 27.79%. Besides, the ${\eta }_{\lim }$ of the double-side SHJ solar cells would exceed the double-side TOPCon solar cells if the recombination parameter of the non-contacted area is higher than 0.6 fA/cm², instead of perfect passivation. Our results are instructive in accurately assessing efficiency potential and accordingly optimizing design strategies of c-Si solar cells.