Buried Interface Modification for Efficient FAPbI₃ Perovskite Modules by Full Blade‐Coating Process

Abstract Large area, dense, and uniform SnO 2 films with fewer defects are essential for high‐quality perovskite films and efficient n‐i‐p typed perovskite modules. In this respect, based on the self‐synthesized SnO 2 nanoparticles (NPs) 4,4′‐bipyridine is introduced as a multifunctional interface modifier at the SnO 2 /perovskite interface. Both experimental and DFT calculation results reveal that, the incorporation of 4,4′‐bipyridine can simultaneously passivate interfacial defects from the SnO 2 surface and perovskite bottom surface. Moreover, it can also facilitate charge carrier transportation. Based on blade‐coating technique for large area perovskite modules, this strategy significantly enhances the interfacial quality of large‐area SnO 2 films and crystal quality of large‐area perovskite layers. As a result, the champion small‐area cell (0.076 cm 2 ) presents the efficiency of 25.75% while the minimodule (22.9 cm 2 aperture area) exhibits the efficiency of 23.50% with a certified efficiency of 22.70%. Both small‐area devices and modules exhibited excellent operation and thermal stabilities, demonstrating that this interface treatment is a promising approach for large‐scale production of high‐efficiency perovskite modules.