Small Molecule-Induced Modulation of Grain Crystallization and Ion Migration Leads to High-Performance MAPbI₃Mini-Modules

Perovskites have become a promising light-absorbing material for the fabrication of high-performance solar cells. But, the relatively low film quality of perovskites hinders the fabrication of large-area perovskite solar modules and long-period stability, which further slows down their industrial-scale commercialization. Here, we propose an N,N′-methylenebis(acrylamide) (MBAA) addition strategy for modulating grain crystallization and ion migration within methylammonium lead halide (MAPbI₃), resulting in enhanced power conversion efficiency (PCE) and stability of MAPbI₃-based solar modules. MBAA can help to form larger perovskite grains with less defects due to strong coordination interactions between the Pb atoms in MAPbI₃and the -NH and -CO functional groups in MBAA. We further found that MBAA was located at the surface of perovskite grains, which would block the ion migration (MA⁺/I^-) and the H₂O/O₂infusion from the ambient-air environment, resulting in enhancements of the PCE and stability of the MAPbI₃devices. The mini-module with an active area of 20 cm²exhibits a record PCE of 18.58%. The MBAA-based solar module shows excellent damp heat and operational stabilities and maintains ∼82% and ∼90% of its initial PCE after 1000 h under 85 °C/85% relative humidity and 1000 h working at the maximum power point.