Cs4PbI6 Assisted Zinc Doping in Pure Red Perovskite with Improved Electroluminescent Performance

B-site doping is an effective strategy to alleviate Pb toxicity and improve the optical properties of mixed halide perovskite. Assisted by zero-dimensional (0D) Cs4PbI6, the zinc ion was successfully incorporated in the CsPbBrxI3-x using facile in-situ solution process and the energy bandgap was enlarged to the pure red region (lambda similar to 636 nm). The Zn-alloyed Cs(ZnyPb1-y)BrxI3-x perovskite film exhibited smoother surface with an improved PLQY of 37.2% than the unalloyed perovskite. Due to the reduction of less conductive 0D perovskite phase, the PeLEDs presented better carrier transport characteristics with evidently improved brightness of 4518 cd/m(2). The Cs(ZnyPb1-y)BrxI3-x PeLEDs also exhibited improved efficiency and superior working stability (T50 @100 cd/m(2) similar to 1.75 h) in comparison to the CsPbBrxI3-x PeLEDs.