Facilitating Electron Transport in Perovskite Solar Cells Through Tailored SnO2 Film Composition

Abstract

The ratio of Sn2+ to Sn4+ plays an essential role in influencing the characteristics of SnO2 film, which is commonly used in the normal structure of perovskite solar cells (PSCs). It is identified that different sequences of addition lead to varying concentrations of Sn2+ and Sn4+ within the SnO2 film. Through this strategic approach, an enhanced SnO2 film with improved electron transport capabilities, a smoother surface texture, and more suitable energy levels are successfully engineered. Consequently, the efficiency of PSCs has seen a notable increase from 22.58% for the control device to 24.16% for the target PSC. Furthermore, PSCs utilizing the optimized SnO2 have demonstrated superior long‐term environmental stability when compared to the control devices. Specifically, PSCs incorporating optimized SnO2 expose to approximately 30% humidity in ambient air for 41 days without encapsulation retain 87% of their initial efficiency. In contrast, the control devices under the same conditions only maintain 77% of their original value.