Efficient and stable Cs5Cu3Cl8-xIx (x = 1,2) single crystalline scintillators for X-ray imaging

The development of materials with high luminescence efficiency and long-term stability remains a central goal in advancing high-performance scintillators. In this study, a series of cesium-copper chloride single crystals incorporating iodine ions were successfully synthesized. These crystals exhibit sufficiently large Stokes shifts for eliminating self-absorption, maintain stability over several months, and achieve a photoluminescence quantum yield exceeding 90 %. These characteristics result in a remarkable radioluminescence light yield of up to 56,100 photons/MeV under X-ray irradiation, with a detection limit of 101 nGy/s and a spatial resolution of 13.9 lp/mm in practical imaging tests. The exceptional luminescent performance is attributed to the unique 1D zigzag chain structures, which enable multiple self-trapped exciton emissions. The large binding energies and strong electron-phonon interaction in these structures facilitate exciton formation and recombination.