Constructing Heterostructure through Bidentate Coordination toward Operationally Stable Inverted Perovskite Solar Cells

It has been reported that one of the influencing factors leading to stability issues in iodine‐containing perovskite solar cells is the iodine loss from the perovskite layer. Herein, bidentate coordination is used with undercoordinated I − of the perovskite surface to construct the stable perovskite‐based heterostructure. This strong halogen bonding effectively inhibits interfacial migration of I − into functional layers such as C 60 and Ag. Moreover, passivation of the undercoordinated I − suppresses the release of I 2 and further delays the formation of voids at the perovskite surface. The resulting inverted perovskite solar cell exhibits a power conversion efficiency of 22.59% and the unencapsulated device maintains 96.15% of its initial value after continuous operation for 500 h under illumination.