Fig. 1: Optimization of vacuum-deposited perovskite films.

a Schematic diagram of tri-source vacuum deposition. b The molecular dipole moment of TPPO and 2-F-TPPO. c Schematic of interaction mechanism between perovskite and 2-F-TPPO, 2-F-TPPO serves as a defect passivator and modulates the crystallization process, and 2-F-TPPO incorporated perovskite film exhibits enhanced PL emission and crystallinity. d UV-vis absorption, e PL and f Time-resolved photoluminescence (TRPL) spectra of films before and after the addition of phosphine oxides