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

The ratio of Sn 2+ to Sn 4+ plays an essential role in influencing the characteristics of SnO 2 film, which is the commonly used in normal structure of perovskite solar cells (PSCs). We have identified that different sequences of addition lead to varying concentrations of Sn 2+ and Sn 4+ within the SnO 2 film. Through this strategic approach, we have successfully engineered an enhanced SnO 2 film with improved electron transport capabilities, a smoother surface texture, and more suitable energy levels. Consequently, the efficiency of PSCs has seen a notable increase from 22.58% of control device to 24.16% for target PSC. Furthermore, PSCs utilizing the optimized SnO 2 have demonstrated superior long‐term environmental stability when compared to the control devices. Specifically, PSCs incorporating optimized SnO 2 , exposed to approximately 30% humidity in ambient air for 41 days without encapsulation, retained 87% of their initial efficiency. In contrast, the control devices under the same conditions only maintained 77% of their original value. This article is protected by copyright. All rights reserved.