Local lattice distortion-driven highly efficient luminescence and thermal quenching resistance in Sb3+-doped hybrid indium chlorides

Abstract

The development of luminescent materials that combine high efficiency with strong thermal quenching resistance remains a key challenge in the field of hybrid metal halides. In this study, we successfully synthesized a zero-dimensional organic–inorganic hybrid metal halide, (C₁₅H₁₈N)₂In_1−xSb_xCl₅, which exhibits highly efficient and thermally stable luminescence. At room temperature, this crystal exhibits bright orange-red broadband light emission and possesses a high photoluminescence quantum yield (PLQY), placing it alongside other efficient emitters in the family of Sb-based hybrid halides. Notably, it demonstrates exceptional resistance to thermal quenching, retaining over 88% of its initial emission intensity from 80 to 300 K and nearly 80% even at 400 K. Density functional theory (DFT) calculations reveal that temperature-induced distortion of the [SbCl₅]²⁻ polyhedron enhances electronic state localization, effectively suppressing non-radiative transitions and partially compensating for thermal quenching. This work provides fundamental insights into the structure–property relationship underlying thermally stable luminescence and offers a practical strategy for designing high-performance optical materials. Based on these properties, the crystal also shows great potential as a reliable luminescent source for optical temperature sensing.