Nonlinear absorption and refraction of Cs3Cu2Br5 perovskite

Halide perovskite (Cs3Cu2Br5) is synthesized by a thermal injection method. The X-ray diffraction (XRD) proves that the Cs3Cu2Br5 crystal phase is an intersection phase. The Cs3Cu2Br5 organic glasses are fabricated by dispersing Cs3Cu2Br5 materials in methyl methacrylate (MMA). The nonlinear absorption (NLA) and the nonlinear refraction (NLR) performances of Cs3Cu2Br5/PMMA organic glasses are measured via the open-aperture (OA) and the closed-aperture (CA) Z-scan technique, respectively. The samples show typical reverse saturable absorption (RSA) and self-focusing effect with the change of input energy (40–72 μJ). Meanwhile, the room-temperature photo-luminescence (PL) measurement reveals light emission for Cs3Cu2Br5. The effects on nonlinear optical (NLO) properties are investigated by controlling the input energy and the amount of the sample. The Cs3Cu2Br5/PMMA organic glasses exhibit excellent NLA and NLR properties. The NLA coefficient of (Cs3Cu2Br5)18/PMMA organic glass is much higher than those of lead-containing perovskite such as CsPbCl3 and CsPbBr3 nanosheets. This results in Cs3Cu2Br5/PMMA organic glasses show superior optical limiting (OL) performance. The Cs3Cu2Br5 perovskite materials show great potential in devices such as light-emitting diodes and optical switches.