Multi-interactions Regulate Perovskite Crystallization and Defect Passivation for Efficient and Stable Perovskite Photovoltaics

High-quality perovskite films are essential for achieving efficient and stable perovskite solar cells (PSCs), requiring precise control over the precursor chemistry, crystallization kinetics, and defect passivation. However, achieving the simultaneous regulation of these coupled factors through a single strategy remains challenging. Here, we introduce sodium hydroxymethanesulfonate (SHMS) as a multifunctional additive to the perovskite precursor to enable a precursor-to-film regulation effect. In the precursor, this multifunctional additive suppresses cation side reactions via electrostatic attraction and hydrogen bonding, while inhibiting the formation of triiodide (I₃^–); in the film, it modulates crystallization kinetics through coordination interactions forming an intermediate complex with PbI₂ and passivates defects to enhance film quality and stability. The resulting inverted PSCs incorporating SHMS achieve a power conversion efficiency of 26.10% (certified value of 25.66%) with a fill factor of 87%, together with excellent thermal, moisture, and light stability. Moreover, when integrated into a solar-charged supercapacitor, the device delivers an overall energy conversion efficiency of 11.84% with an outstanding cycling stability.