Electronic structure and optical properties of doped γ-CuI scintillator: a first-principles study

A cuprous iodide (CuI) crystal is considered to be one of the inorganic scintillator materials with the fastest time response, which is expected to play an important role in the field of gamma and X rays detection in the future. To improve the detection performance of the CuI scintillator, the effects of element doping on the electronic structure and optical properties of the gamma-CuI were investigated by using the first principles calculation method. It was found that Li and Na doping increases the band gap of the gamma-CuI scintillator, while Cs, F, Cl, and Br doping decreases the band gap. The optical absorption coefficient of the gamma-CuI scintillator is decreased by the Li and Na doping, and the Cs, F, Cl, and Br doping has little effect on the optical absorption coefficient. The effects of the Tl doping on the electronic structure and optical properties of the gamma-CuI scintillator depends on its concentration. Based on the changes in the electronic structure and optical properties, we conclude that the Cs, F, Cl, and Br doping might be a good method that can enhance the detection performance of the gamma-CuI scintillator.