Supramolecular Strategy for Constructing Mixed Coordination Units toward Ultra-Stable White-Light Emission in Zero-Dimensional Hybrid Indium Chloride

Intensive research into single-component white-light-emitting materials is extremely valuable for innovating next-generation solid-state lighting technology. Herein, we innovatively propose a crown ether-assisted supramolecular self-assembly strategy that is supported by the construction of mixed coordination units in low-dimensional hybrid metal halides (LHMHs). The resultant [(C10H20O5)InCl2]InCl4 is an extremely rare class of zero-dimensional (0D) indium-based chloride that is featured by the structurally deformable mixed coordination units of 7-coordinated [InCl2O5] (In-1) and 4-coordinated [InCl4] (In-2). Excitingly, it exhibits a high-quality white-light emission with a full width at half-maximum (fwhm) of 211 nm and a photoluminescence quantum yield (PLQY) of 33.6%, which is attributed to the unprecedented intrinsic dual self-trapped excitons (STEs) under electron-phonon coupling. The electron-transition mechanism is elucidated according to temperature-dependent PL spectra and theoretical calculations. Beyond that, the indium-based white-light emitter possesses superb water stability because of the hydrophobicity of 15-crown-5, which is unachievable for almost all LHMHs. This work sheds light on an executable self-assembly strategy for building mixed coordination units and extends to the design of single-component white-light-emitting materials.