Regulating Exciton Diffusion in Antimony‐Based Perovskite‐Like Single Crystals toward Highly Efficient and Stable Luminescence

Abstract Organic‐inorganic hybrid metal halide perovskite has played an important role in optoelectronics and photonics due to their extremely high photoluminescence quantum yield (PLQY). However, considering the strong nonmetallic property of antimony (Sb), the excitons in antimony‐based single crystals are usually dissipated in the form of non‐radiative recombination under organic‐inductive effect, which leads to the low PLQY. Herein, two kinds of perovskite‐like single crystals, i.e., (8‐HQ)₂SbCl₃ and (8‐HQH)SbCl₄, are innovatively grown. The density functional theory (DFT) calculations reveal that the unique luminescence characteristics are associated with the inductive effect of organic coordination and exciton effect in the metal octahedral skeleton. When Cl⁻ replaces the organic ligand in (8‐HQ)₂SbCl₃, the inductive effect is reduced while the self‐trapped exciton effect in the metal octahedron is enhanced. Besides, the theoretical research on electron transmission in a modeling device reveals that the hydrogen bond of organic A‐site in the single crystal promotes the transition of electrons. Based on the luminescent properties of (8‐HQH)SbCl₄, the white LED devices are obtained by coating (8‐HQH)SbCl₄ and red phosphor on 450 nm LED chips.