Theoretical study of the MAPbI3/SnO2 interface band offset in perovskite solar cells considering mobile ions

This work investigates the band offset influence at the MAPbI 3 /SnO 2 interface by an electronic-ionic drift-diffusion model with an emphasis on utilizing realistic band offset values. We validate the model by comparison with experimental measurements and discuss the effect of different concentrations of fast positive and slow negative ions in the perovskite layer. Band offset < 0.1 eV at the perovskite/electron transport layer interface is proposed to allow ideal carrier transport with negligible hysteresis, regardless of the presence of mobile ions. Reducing the band offset thus stands out as a more feasible way to optimize the performance of perovskite and perovskite/silicon-based tandem solar cells.