Blade‐Coated Scintillation Films with High Spatial Resolution Enabled through Solvent Engineering

ABSTRACT 0D Cs ₃ Cu ₂ I ₅ has attracted considerable attention for radiation detection and imaging owing to its outstanding properties, including a high photoluminescence quantum yield, large Stokes shift, and high X‐ray attenuation coefficient. However, the fabrication of large‐area scintillator films remains challenging due to issues such as low solid content in polymer‐based flexible composites, the formation of porous structures in sintered pellets, and complex processing requirements. To overcome these limitations, we propose a facile paste blade‐coating approach combined with solvent engineering to fabricate highly uniform Cs ₃ Cu ₂ I ₅ scintillator films with size of 7.5 × 7.5 cm ² . The influence of different solvents on the morphology and performance of the films was systematically studied. Results demonstrate that dimethyl sulfoxide (DMSO), with its strong coordination capability and high solubility, significantly improves particle dispersion and promotes the formation of dense films, leading to enhanced light transmittance and higher radioluminescence intensity. Consequently, the DMSO‐optimized Cs ₃ Cu ₂ I ₅ film achieves a light yield of 54,008 photons MeV ^{− 1} and a spatial resolution of 16 lp mm ^{− 1} , demonstrating great potential for large‐area dynamic X‐ray imaging. This work offers insights into the morphological control and scalable fabrication of halide scintillators, and presents an effective strategy for producing high‐performance scintillator films.