Zero-Dimensional Hybrid Indium Halides with Efficient and Tunable White-Light Emissions

Two-dimensional hybrid lead perovskites have attracted a great deal of attention in white-light-emitting diodes, but the serious toxicity of Pb²⁺ and the limited photoluminescence quantum yield (PLQY) still restrict further optoelectronic application. To address these issues, a new combining photon strategy was proposed to achieve highly efficient broadband white-light emission in a new family of zero-dimensional (0D) indium halides based on an [InCl₆]^3- octahedron. Remarkably, these 0D halides display dual-band white-light emission derived from the synergistic work of blue- and yellow-light-emitting bands, which can be ascribed to the radiative recombination of bound excitons in organic cations and self-trapped excitons in inorganic anions, respectively, based on spectroscopy and theoretical studies. In-depth first-principles calculation demonstrates that the increased structural deformability effectively improves the PLQY from 7.01% to 18.56%. As a proof of concept, this work provides a profound understanding for advancing the rational design of novel single-component 0D lead-free halides as high-performance white-light emitters.