A highly luminescent copper (I) halide complex scintillator for X-ray imaging application

Copper (I) halide complexes have garnered much attention due to their straightforward synthesis, high luminescence efficiency, and structural diversity. In this work, a new class of Cu 2X2L2 complexes (X = Cl, Br, and I; L = 2-(dicyclohexyl)-2-(N, N-dimethylamino) biphenyl) were synthesized. Among them, the Cu 2I2L2 complex exhibits a broad emission band and a high photoluminescence quantum yield of nearly 100%. Time-dependent density functional theory calculations reveal that the emission of Cu 2I2L2 stems primarily from the mixed metal/halogen-to-ligand charge transfer state. Notably, the Cu 2I2L2 complex exhibits a light yield of 38297 photons MeV -1 and an ultra-low detection limit of 49.4 nGy s -1 . The scintillation film fabricated from Cu2I2L2 enables high-resolution X-ray imaging with a spatial resolution of 10 lp mm -1 . These results underscore the promising potential of Cu 2I2L2 as an excellent scintillator for advanced X-ray imaging applications.