Adjusting the nonlinear optical and optical limiting properties of MAPbBr₃/PMMA by doping with Zn

Third-order nonlinear optical and optical limiting properties of MAPbBr₃/polymethyl methacrylate (PMMA) are adjusted by doping with Zn. X-ray diffraction and photoluminescence are performed to confirm the effective doping of Zn. Typical reverse saturable absorption and self-focusing effects are observed in the undoped MAPbBr₃/PMMA and Zn-doped MAPbBr₃/PMMA. After Zn doping, the nonlinear absorption coefficient becomes larger but nonlinear refraction coefficient becomes smaller. This may be related to the decreased defect states after Zn doping. Besides, both values of the optical limiting threshold and the clamping normalized transmittance for the Zn-doped MAPbBr₃/PMMA are obviously smaller than those of the undoped sample, indicating that its optical limiting property enhances. The reverse saturable absorption properties are caused by one photon absorption-induced excited-state absorption processes, which have been explained by using three-energy-level diagrams. The nonlinear optical and optical limiting properties of the Zn-doped MAPbBr₃/PMMA make it show great potentials for application in optical limiter.