Nonlinear optical properties of benzylamine lead(II) bromide perovskite microdisks in femtosecond regime

Abstract

Organometal halide perovskites, an emerging class of direct bandgap semiconductors, are attractive candidates for many optoelectronic device applications. Herein, we have reported the nonlinear optical (NLO) properties of layered benzylamine lead(II) bromide perovskite microdisks (MDs) having a lateral dimension of a few micrometers and an average thickness of 35 nm, featuring narrow deep blue emission using the Z-scan technique. The NLO behavior switches over from saturable absorption to reverse saturable absorption under femtosecond laser pulse excitation. Our NLO studies have demonstrated tunable nonlinear behavior, which is attributed to the interplay between single and two-photon absorption by the carriers in the conduction band. Perovskite MDs exhibit an optical limiting behavior originating from the two-photon absorption mechanism.