Synergistically Regulating CBD‐SnO2/Perovskite Buried Interface for Efficient FAPbI3 Perovskite Solar Cells

Abstract

AbstractTin oxide (SnO2) based on chemical bath deposition method (CBD‐SnO2) is considered as an ideal electron transporting layer for perovskite solar cells (PSCs), however, the research on precise regulation toward CBD‐SnO2 layer is lacking. Here, the study introduces a multifunctional molecule, potassium 2‐(N‐morpholino)ethanesulfonate (MES‐K), on the surface of CBD‐SnO2 layer to synergistically modify the buried interface between the SnO2 and perovskite. It is found that MES‐K introduction can passivate interfacial defects, favor the perovskite crystal growth, and improve carrier transportation. 25.14% efficiency of small‐size perovskite solar cells has been achieved with 24.45% efficiency of 1 cm2 perovskite devices, with negligible hysteresis. Besides, unencapsulated devices based on CBD‐SnO2 can maintain > 95% of its initial efficiency after 2000 h storage at ambient environment, and > 90% after 1000 h LED illumination.