Stable Intrinsic White-Light Emission in F-Doped 2D Zinc Halide Perovskites by Self-Trapped Exciton and Defect Passivation

Two-dimensional (2D) organic–inorganic hybrid metal halide perovskites (MHPs) are promising as semiconducting light-emitting materials due to improved environmental stability and unique optical properties, compared with three-dimensional MHPs. However, toxic Pb and relatively low photoluminescence quantum yield (PLQY) limit the potentials of these 2D lead halides in solid-state lighting. Herein, we report a series of F-doped, 2D zinc halide-layered perovskites based on phenylethylamine (PEA), PEA 2 ZnF x Cl 4– x, which exhibits efficient white light and the highest PLQY of 21.02% at x = 0.40, seven times higher than that of non-F doping samples for 2D hybrid white-light-emitting MHPs. Steady-state and temperature-dependent optical measurements verify that the white-emission arose from self-trapped excitons and highlight the significant effects of F-doping and defect passivation on efficient photoluminescence. Especially, F-doped 2D zinc halide perovskites show ultrahigh stability with negligible degradation for 1000 h at 80 °C. This work paves an avenue to designing efficient and stable single-component white-light-emitting diodes in solid-state lighting.