Application of n-Polysilicon Rear Emitter for High-Efficiency p-TOPCon Solar Cells

This study entails the examination of tunnel oxide passivated contact on p-type silicon wafers (p-TOPCon) passivated with n-polysilicon for a solar cell by using Quokka-3, a numerical simulation program. The effects of the thickness, bulk lifetime, resistivity, and selectivity of charge carriers due to the polysilicon passivated contact are investigated. Through such n-polysilicon passivated contact, the back-emitter solar cells engender higher internal power owing to enhanced surface passivation. This further reduces the shading loss due to front metallization; however, the reduced minority carrier lifetime of the p-type Czochralski (Cz) wafer restricts the possibilities for high efficiency. Subsequently, the minority charge carrier lifetime of the p-type wafer conceivably becomes an obstacle to realizing TOPCon solar cells with a high conversion efficiency. This study demonstrates that a configuration suitable for the industrial manufacturing of high-efficiency solar cells is a crystalline silicon solar cell on a p-type wafer through a rear-emitter n-polysilicon passivated contact. A roadmap toward 24.87% of the p-TOPCon solar cells through the n-type polysilicon passivated contact is also devised.