Ammonia Borane All-In-One Modification Strategy Enables High-Performance Perovskite Solar Cells

An all-in-one modification strategy was developed by introducing a multifunctional complex ammonia borane (BNH 6 ) into the buried and upper interfaces simultaneously. BNH 6 uniquely realizes dual-interfacial defect passivation and iodide oxidation suppression by interacting with SnO 2 through hydrolysis, coordinating with Pb 2+ and inhibiting the oxidation of I − . The optimized perovskite solar cells achieve a champion efficiency of 26.43% (certified, 25.98%) with negligible current density–voltage hysteresis and significantly improved thermal and light stability.