Fig. 1: Characteristics of perovskite films with different EABr.

a Normalized steady photoluminescence (PL) spectra. b UV–vis absorption spectra, and c Photoluminescence quantum yield (PLQY) spectra. d Normalized PL spectra of quasi-2D perovskite film with 60% EABr under continuous UV radiation (360 nm, 1 mW cm−2) for different exposure times. e Normalized PL spectra of quasi-2D perovskite film with 60% EABr after continuous thermal treatment (60 °C) for different times.