Dynamic origins of cation-modulated stability in tin-based perovskites revealed through combined fine-tuned machine learning interatomic potentials and experiments

Fine-tuned MLIP-MD reveals cation-dependent degradation of Sn-based perovskites, showing Cs suppresses water penetration, pristine FAMASnI 3 undergoes physical dissolution, and Rb triggers I − loss and Sn–O oxidation leading to severe structural failure.