The impact of bulk resistivity on bifacial n-PERT rear junction solar cells

Abstract

This work mainly focuses on the impact of bulk resistivity (ρ b ) on bifacial n-type passivated emitter rear and totally diffused rear-junction (n-PERT-RJ) solar cells. Through simulation, under front illumination, the light-generated excess carrier flow behavior in the bulk is studied. The regulatory function of the rear junction solar cells' bulk on the electron flows distributary is discussed. Finally, how the different ρ b values affect the hole-current flow behavior and the FSF performance is revealed. This explains very well the reasons for decreasing short-circuit current (J sc ) due to the low ρ b wafers in n-PERT-RJ solar cells. The studies also provide insights on the lowest value of pb which can be applied to n-PERT-RJ solar cells without efficiency deterioration. We also simulated n-PERT-RJ solar cell performance and bifaciality when applying different ρ b values under rear illumination. Last but not the least, investigation on how ρ b affects the output performance will be extended to when n-PERT-RJ solar cells are served as the bottom subcell in a four-terminal (4T) tandem configuration.