Antimony-doping induced highly efficient warm-white emission in indium-based zero-dimensional perovskites

Abstract

Indium (In)-based halide perovskites are desirable for next-generation phosphors and emitting devices, due to their broad emission, nontoxicity, and oxidization avoidance capabilities. However, the In-based perovskites always exhibit low external photoluminescence quantum efficiency (PLQE) as a result of their weak light absorption near the corresponding excitation region, and thus, are limited in extended applications. Herein, we have developed an antimony (Sb)-doping strategy to improve the absorption ability of Cs2InCl5H2O in the ultraviolet region. Excitingly, we obtained a warm-light phosphor with ultrahigh external (internal) PLQE of 72.8% (86.7%). Typically, upon 1.5% Sb doping, the single-crystalline Cs2InCl5H2O perovskite displayed a stronger warm-light emission at ∼ 610 nm with a large Stokes shift of 295 nm and full width at half maximum (FWHM) of 164 nm. Density functional theory (DFT) calculations revealed that the Sb-doping induced an impurity level in the bandgap, increasing the density of state (DOS), and promoted more carriers into the conduction band maximum. Furthermore, external PLQE from 18% to 59% could be realized in other zero-dimensional In-based perovskites through the same doping strategy.