Achieving Highly Efficient Orange Emission in Tin (IV)‐Based Metal Halides with Outstanding Anti‐Water Stability Through Antimony Doping and Reasonable Structural Modulation

Abstract Recently, 0D metal halides have attracted widespread interest because of their diverse structures and rich luminescence properties. Nevertheless, the controllable synthesis of metal halide clusters with the ideal configuration using chemical methods remains a great challenge. In addition, the relationship between the coordination configuration and the optical properties of 0D metal halides is not well understood. In this study, two homologous Sb 3+ ‐doped 0D Sn (IV)‐based metal halides with different coordination configurations are developed by inserting a single organic ligand, tetrabutylphosphonium chloride (TBPCl), into a SnCl 4 lattice, resulting in different optical properties. Under photoexcitation, Sb 3+ ‐doped (TBP)SnCl 5 ·DMF shows a negligible luminescence from the organic cation of TBP + , while Sb 3+ ‐doped (TBP) 2 SnCl 6 shows a bright orange emission band at 650 nm with a photoluminescence quantum yield (PLQY) of 99%. The above two compounds show quite different optical properties, which should be due to the too‐large lattice distortion of Sb 3+ ‐doped (TBP)SnCl 5 ·DMF, and the DMF will cause the efficient non‐radiation relaxation. In particular, Sb 3+ ‐doped (TBP) 2 SnCl 6 exhibits remarkable anti‐water stability, which shows stability in water for 48 h without structural degradation, and the luminous intensity remains at a high level. Combined with its excellent optical properties and impressive stability, Sb 3+ ‐doped (TBP) 2 SnCl 6 is used in white‐light‐emitting diodes (WLED).