Bulk Coassembly of Zero-Dimensional Heterometallic Halide Hybrids for Broadband White Light Emission and Optical Thermometry

Multicomponent heterometallic zero-dimensional (0D) halide hybrids are an emerging class of solid-state materials with multiple functionalities due to the unique electronic properties of the constituent metal halide units. However, the synthesis of such a multicomponent single-phase material, incorporating two or more distinct metal halide units, is challenging due to the preferential crystallization of the one-component structure. Here, we report a single-crystalline bulk assembly of the 0D heterometallic halide hybrid, (Et4N)(4)(MnCl4)(SbCl5) (Et4N = tetraethylammonium), incorporating disparate metal halide units. The heterometallic halide hybrid, featuring isolated Mn halide (tetrahedral) and Sb halide (square pyramidal) units, shows multimodal emission: green emission (from the Mn halide unit) and blue and orange emissions (from the singlet and triplet Sb halide units, respectively). Minimum electronic coupling between the isolated metal halide units and strong (near-unity PLQY) multimodal emission facilitate precise color control by tuning the excitation wavelengths. The combination of individual emissions results in a strong white light emission (0.33, 0.40; CCT = 5500 K) without utilizing a secondary down-converting blue light source. Relative amounts of constituent metal halide units further tune the emission color with CCT values ranging from 6379 to 3567 K. The thermochromism observed herein is exploited for optical thermometry with an absolute sensitivity of similar to 0.058 K-1 in the temperature range of 30-100 degrees C. This coassembly-based synthetic strategy opens new synthetic avenues to access multifunctional solid-state lighting materials.