Highly efficient blue emissive copper halide Cs5Cu3Cl6I2 scintillators for X-ray detection and imaging

In recent years, copper-based halide scintillators have attracted tremendous attention due to their excellent luminescent properties and low manufacturing costs. Herein, a high-performance and low-cost Cs5Cu3Cl6I2 scintillator is prepared by simple mechanical grinding. The mixed-halide Cs5Cu3Cl6I2 phosphor exhibits a blue emission centered at 475 nm with a large stokes shift, originating from the self-trapped exciton emission of Cu sites. The photoluminescence quantum yield (PLQY) of Cs5Cu3Cl6I2 can be increased to 88.4% from 20.4% by the efficient suppression of the anion vacancy defects. In addition, the Cs5Cu3Cl6I2 scintillator shows a high steady-state X-ray to light conversion efficiency of about 57000 photons/MeV, good X-ray linear response, and low detection limit of 71.9 nGyair/s. The X-ray imaging results based on the Cs5Cu3Cl6I2 scintillator screen display a high spatial resolution of 9.0 line-pairs per millimeter (lp/mm). Furthermore, Cs5Cu3Cl6I2 exhibits good radiation stability under a total dose of 113.58 Gyair. Overall, the Cs5Cu3Cl6I2 scintillator prepared by mechanical grinding method has the advantages of low cost, high efficiency, and good radiation resistance, suggesting its huge potential in X-ray detection and imaging.