Tunable Bright White Light Emission with Ultra‐High Color Rendering Index Induced by Trigonal Bipyramid Unit

Abstract Efficient broadband emitting organic–inorganic metal hybrids (OIMHs) have attracted great attention recently as promising single‐component white light emitters. Here a new zero‐dimensional (0D) OIMH (C 13 H 14 N) 2 InCl 5 (C 13 H 14 N + = N ‐methyldiphenylammonium) is reported, which features unique five‐coordinated [InCl 5 ] 2− trigonal bipyramid motif. For the first time, it is demonstrated that the trigonal bipyramid units in 0D OIMH can act as luminescence centers, showing blue emission under UV light. Remarkably, incorporating Sb 3+ in [InCl 5 ] 2− trigonal bipyramids induces a new dual‐band emission at 540 and 735 nm resulting from the singlet and triplet self‐trapped excitons in [SbCl 5 ] 2− , leading to complete coverage of the entire visible spectrum. The resulting emissions in (C 13 H 14 N) 2 InCl 5 :Sb 3+ are tunable from cold to warm white with the correlated color temperatures changing from 5574 to 3473 K and more importantly, an ultra‐high color rendering index (CRI) up to 96 being observed, which is comparable to the highest value in hybrid metal halides. A high photoluminescence quantum yield of 46.26% is simultaneously obtained in this system. This work demonstrates that the 0D OIMH with trigonal bipyramid motif is an excellent system for realizing the single‐component white light emission with both high efficiency and ultra‐high CRI.