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First principles study electronic and optical properties of LaBr3 and LaBr3:Ce crystal

First-principles calculations based on the density function theory (DFT) are implemented to explore the effect of Ce doping on the electronic structure and optical properties of LaBr3 crystals using generalized gradient approximation (GGA) +U. And band structure, density of states and optical properties are discussed. Due to the transition of Ce3+ ion from 4f-orbital to 5d-orbital, the band gaps of LaBr3:Ce (0.63 eV) is narrower than that of LaBr3 (3.569 eV), which produce more visible light in the same range of irradiated energy. Otherwise, the absorption spectrum (15.6 μm-1) and reflection index (less than 12%) of LaBr3:Ce are smaller than LaBr3 (20 μm-1, less than 15%, respectively), leading to transmit more visible light. The research shows reason that Ce doping can improve the luminescence performance of LaBr3 scintillators and the results are compared with the available experimental data.