Bright luminescence of Sb doping in all-inorganic zinc halide perovskite variant

•All-inorganic zinc halide perovskite variant Cs2ZnCl4 crystals with Sb3+ doping are synthesized via hydrothermal method•Crystals exhibit self-trapped exciton emission, which is attributed to the transition from 3P1 to 1S0 states of Sb3+.•Temperature-dependent and time-resolved photoluminescence reveal the emission evolution with temperature.•Calculations reveal the influences of Sb3+ doping in Cs2ZnCl4, including bandgap reduction and band edge localization.