Surface engineering for enhanced efficiency and stability of perovskite solar cells through Lewis acid-base modified tin oxide electron transport layers

Abstract

The effective utilization of Lewis acid-base reactions plays a pivotal role in achieving high power conversion efficiency (PCE) in perovskite solar cells while ensuring exceptional stability. In this study, we introduce the Lewis acid-base reaction as a potent modification technique for enhancing the performance of the tin oxide (SnO2)-based electron transport layer (ETL) in perovskite solar cells. Devices employing this modified ETL exhibit an impressive efficiency of 22.2%, surpassing the reference devices with a single SnO2 ETL, which achieve only 19.5% efficiency. Moreover, these Lewis acid-base-modified ETLs demonstrate outstanding stability, retaining over 90% efficiency even after 1000 h of exposure under AM 1.5G lamp irradiation with negligible hysteresis effects. Further investigation reveals that the performance enhancement can be attributed to various mechanisms. The Lewis acid-base reaction not only mitigates inherent defects within the SnO2 layer but also significantly improves the deposition of subsequent perovskite layers. Our research makes a substantial contribution to the advancement of perovskite solar cell technology, providing a promising avenue for more efficient and durable energy conversion devices.