Tunable White Light Emission in a Zero‐Dimensional Organic–Inorganic Metal Halide Hybrid with Ultra‐High Color Rendering Index

Abstract Organic–inorganic metal halide hybrids (OIMHs) with broadband white light (WL) emission are considered as a new type of rare‐earth‐free phosphors. Herein, eco‐friendly and stable Sn(IV) is selected as the B ‐site inorganic cation to synthesize a 0D lead‐free OIMH (C 5 N 2 H 14 )SnCl 6 , in which the isolated [SnCl 6 ] 2− octahedra are separated by large organic [C 5 N 2 H 14 ] 2+ cations. Under different excitations, this compound exhibits warm white emission with a tunable color rendering index (CRI) from 80 to 97, the highest value among all known OIMHs, owing to the synergistic effect of [C 5 N 2 H 14 ] 2+ and [SnCl 6 ] 2− octahedra. This work presents a new strategy toward the WL materials with ultra‐high CRI by co‐regulating organic cations and inorganic polyhedra.