Supramolecular\nStrategy for Constructing Mixed Coordination\nUnits toward Ultra-Stable White-Light Emission in Zero-Dimensional\nHybrid Indium Chloride

Intensive research into single-component white-light-emitting\nmaterials\nis extremely valuable for innovating next-generation solid-state lighting\ntechnology. Herein, we innovatively propose a crown ether-assisted\nsupramolecular self-assembly strategy that is supported by the construction\nof mixed coordination units in low-dimensional hybrid metal halides\n(LHMHs). The resultant [(C<sub>10</sub>H<sub>20</sub>O<sub>5</sub>)InCl<sub>2</sub>]InCl<sub>4</sub> is an extremely rare class of\nzero-dimensional (0D) indium-based chloride that is featured by the\nstructurally deformable mixed coordination units of 7-coordinated\n[InCl<sub>2</sub>O<sub>5</sub>] (<b>In-1</b>) and 4-coordinated\n[InCl<sub>4</sub>] (<b>In-2</b>). Excitingly, it exhibits a\nhigh-quality white-light emission with a full width at half-maximum\n(fwhm) of 211 nm and a photoluminescence quantum yield (PLQY) of 33.6%,\nwhich is attributed to the unprecedented intrinsic dual self-trapped\nexcitons (STEs) under electron–phonon coupling. The electron-transition\nmechanism is elucidated according to temperature-dependent PL spectra\nand theoretical calculations. Beyond that, the indium-based white-light\nemitter possesses superb water stability because of the hydrophobicity\nof 15-crown-5, which is unachievable for almost all LHMHs. This work\nsheds light on an executable self-assembly strategy for building mixed\ncoordination units and extends to the design of single-component white-light-emitting\nmaterials.