Halogen-Driven Tetrahedral Distortion Enables Tunable White-Light Emission and Scintillation Properties in Hybrid Zinc Halides

Abstract Organic–inorganic hybrid zinc halides have emerged as promising luminescent materials for solid-state lighting and radiation detection owing to their facile synthesis, tunable crystal structures, and rich photophysical behaviors. Herein, we report two hybrid zinc halides, (C5H14N2)ZnCl4·0.5H2O (Cl4) and (C5H14N2)ZnBr4·H2O (Br4), wherein halogen substitution from Cl– to Br– successfully achieves tunable white-light emission with color coordinates of (0.23, 0.25) for Cl4 and (0.26, 0.29) for Br4, originating from the synergistic contribution of singlet and triplet excited states. Benefiting from the favorable crystal-field environment of the bromide host, Mn2+ ions are further introduced into the Br4 lattice via an N-ion-doping strategy. The incorporated Mn2+ activators endow Br4 with prominent radioluminescence under X-ray excitation, and the optimized Br4:0.6Mn2+ exhibits a light yield of 16900 photons/MeV and a detection limit of 1.28 μGyair/s. Further, a spatial resolution of 7.6 Lp/mm is achieved in X-ray imaging based on the flexible Br4:0.6Mn2+@PDMS films. This work establishes a straightforward anion engineering strategy to simultaneously realize white photoluminescence and efficient X-ray scintillation within a single hybrid zinc halide system, providing a facile route toward multifunctional luminescent materials for white-light illumination and high-performance X-ray imaging.