Realizing Tunable White Light Emission in Lead-Free Indium(III) Bromine Hybrid Single Crystals through Antimony(III) Cation Doping.

Low-dimensional metal halide hybrids (OIMHs) have recently been explored as single-component white-light emitters for use in solid-state lighting. However, it still remains challenging to realize tunable white-light emission in lead-free zero-dimensional (0D) hybrid system. Here, a combination strategy has been proposed through doping Sb enabling and balancing multiple emission centers toward the multiband warm white light. We first synthesized a new lead-free 0D (CNH)InBr·HO single crystal, in which isolated [InBr] octahedral units are separated by large organic cations [CNH]. (CNH)InBr·HO exhibits dual-band emissions with one intense cyan emission and a weak red emission tail. The low-energy ultrabroadband red emission tail can be greatly enhanced by the Sb doping. Experimental data and first-principles calculations reveal that the original dominant cyan emission is originated from the organic cations [CNH] and that the broadband red emission is ascribed to self-trapped excitons in [In(Sb)Br]. When the Sb concentration is 0.1%, a single-component warm white-light emission with a photoluminescence quantum efficiency of 23.36%, correlated color temperature of 3347 K, and a color rendering index up to 84 can be achieved. This work represents a significant step toward the realization of single-component white-light emissions in environmental-friendly, high-performance 0D metal halide light-emitting materials.