Stabilizing Tin-Lead Mixed Perovskite Solar Cells: A Spotlight on Antioxidation Strategies

Tin-lead (Sn-Pb) mixed perovskites have emerged as promising light-absorbing materials for single-junction and all-perovskite tandem solar cells due to their favorable narrow bandgaps and high theoretical power conversion efficiencies. However, the easy oxidation of Sn2+ to Sn4+ results in the formation of rampant defects during the fast crystallization of Sn-Pb mixed perovskite thin films and remarkable photovoltaic performance decay under operation, impeding their practical applications. Herein, this spotlight presents the intrinsic origins of Sn2+ instability and summarizes recent advances in the antioxidation strategies of Sn-Pb mixed perovskites regarding raw material purification, additive engineering, composition engineering, and interfacial engineering. Then, the remaining challenges and future directions are discussed to inspire more rational antioxidation design toward efficient and durable Sn-Pb mixed perovskite solar cells.