Thin films of MAPbI3 and MA0.15FA0.75Cs0.1PbI3 perovskites under femtosecond laser irradiation: nonlinear optical absorption and kinetics of photodegradation

The thin MAPbI3 and MA0.15FA0.75Cs0.1PbI3 perovskite films have strong nonlinear absorption with coefficients of 443 ± 20 and 830 ± 50 cm GW–1, respectively, due to two-photon absorption at 1064 nm. The photochemical degradation of perovskite films was observed upon irradiation with femtosecond pulses at 532 nm, and the depth of photodegradation decreased in perovskite films protected with a PMMA polymer layer.