In Situ Fabrication of Cs3Cu2I5: Tl Nanocrystal Films for High-Resolution and Ultrastable X-ray Imaging

Cs3Cu2I5nanocrystals (NCs) are considered to be promisingmaterials due to their high photoluminescence efficiency and X-ray hardness.However, the present strategy depends on tedious fabrication with excessivechemical waste. The evasive iodide ion dissociation, inadaptable ligand system, lowstability, and relatively low light yield severely impede their applications. Herein, wedevelop an in situ fabrication strategy for aflexible and large-area Tl-doped Cs3Cu2I5NC-polymer composite scintillationfilm with a high light yield (similar to 48800 photons/MeV) and improved stability. Tween 80 and phosphinic acid successfully inhibit theoxidation of iodide ions, and thefilms can be stored for at least six months. As aresult, a high spatial resolution of 16.3 lp mm-1and a low detection limit of 305nGyairs-1were achieved. A radioluminescence intensity of >80% was maintainedafter a total irradiation dose of 604.8 Gy. These results indicate the promising application of these copper halide NCs in low-cost,flexible, and high-performance medical imaging.