Halogen Tailoring Enables Large-Area Mn-Based Halide Single-Crystal Films with Enhanced Radioluminescence and High-Resolution X-ray Imaging.

For hybrid metal-halide scintillators, achieving a concurrent increase in both radioluminescence efficiency and image-resolving capability represents a substantial hurdle toward high-performance X-ray imaging applications. Herein, we report a collaborative strategy integrating halogen regulation with a spatial-confinement growth method to synergistically optimize Mn-based scintillators and fabricate large-area single-crystal films. Precise Cl/Br/I modulation dramatically increases the photoluminescence quantum yield from 32.68 to 96.74% and boosts the light output by 73 to 243% LYSO in optimized MTP2MnCl4. The DFT calculations further elucidate their luminescence mechanism, indicating that the valence band maximum (VBM) originates mainly from Mn_3d and X_np orbitals, while the Mn2+ ions within the [MnX4]2- tetrahedra function as efficient exciton acceptors and radiative centers. Concurrently, the developed space-confined solution-growth method enables the preparation of high-quality, single-crystal films. Owing to their excellent transparency and negligible light scattering, these films achieve an outstanding spatial resolution reaching 31.2 lp/mm, surpassing most reported polycrystalline and film-based scintillators. This work presents a unified material-to-device approach that jointly boosts both scintillation yield and imaging resolution, thereby providing a versatile platform for next-generation high-resolution radiography and security inspection.