Multisite Passivation and Surface Reconstruction of Perovskite for All-Air-Fabricated Perovskite Solar Cells

Molecular passivation of interfacial defects represents a key pathway toward high-performance perovskite solar cells (PSCs), yet its success hinges on the formation of robust and functional bonds with the perovskite lattice. Weak or limited interactions at the perovskite/hole transport layer (HTL) interface often led to insufficient passivation, accelerated ion migration, and compromised morphological stability, ultimately resulting in a rapid performance degradation. Here, we prepare 2-aminothiazoline hydrochloride (ATZCl) as a multifunctional passivator that forms multidentate binding and reconstructs the perovskite surface through the subsequent spontaneous growth of an RP-like surface phase. This synergistic interaction effectively suppresses defect states, minimizes nonradiative recombination, and enhances charge extraction at the critical perovskite/HTL interface. Time-of-flight secondary-ion mass spectrometry analysis corroborates that the ATZCl interlayer significantly suppresses iodine ion migration across the perovskite/HTL stack. Consequently, our strategy enables the all-air fabrication of high-performance PSCs, achieving a champion power conversion efficiency of 25.22% alongside markedly improved operational stability.