Using a Novel Melt-Cooling Crystallization Method to Prepare High-Quality Cs ₃ Cu ₂ I ₅ X-ray Scintillators

Copper halide, as a highly attractive and promising type of scintillator, has attracted a great deal of attention in the field of X-ray imaging. However, controllable preparation of copper-based halide perovskite films with uniformity, large size, high radiation stability, and excellent scintillation performance remains a major challenge. Herein, we propose a melt-cooling crystallization method to prepare high-quality Cs3Cu2I5 perovskite powder blocks with uniform size in batches, grind the perovskite powder blocks into uniformly fine particles, and mix them with polydimethylsiloxane (PDMS) to obtain large-area, highly stable, and excellent-scintillation-performance perovskite scintillator films. The Cs3Cu2I5 scintillator film exhibits a large Stokes shift (141 nm) and a photoluminescence quantum yield of up to 92.1%, effectively ensuring the decoupling efficiency of light. Moreover, the large-area scintillator film (20 × 16 cm2) obtains a low detection limit (40.29 nGy/s) and a spatial resolution up to 11.7 lp/mm. Meanwhile, the Cs3Cu2I5 scintillator film has excellent flexibility and can maintain its original appearance even after more than 1000 continuous stretching and bending cycles. Finally, high-quality X-ray imaging of different objects by scintillators is demonstrated. These results highlight the application prospects of Cs3Cu2I5 scintillator films in low-cost, high-performance, large-area, and flexible imaging.