Crystal structure, electronic structure, temperature-dependent optical and scintillation properties of CsCe2Br7

摘要: CsCe2Br7 is a self-activated inorganic scintillator that shows promising performance, but the understanding of important structure–property relationships lacking. In this work, we conduct comprehensive study on CsCe2Br7. The crystal structure refined using single X-ray for first time. It crystallizes into orthorhombic system with Pmnb space group. Its electronic revealed by density functional theory (DFT) calculations. Two cerium emission centers are identified and energy barriers related to thermal quenching 4f ground states Ce3+ these two Ce evaluated. has better light yield resolution than CsCe2Cl7, an additional slow decay component 1.7 μs. existence deep trap depth 0.9 eV in CsCe2Cl7 contributes its higher afterglow level comparison most possible point defects proposed considering vapour pressure growth atmosphere upon melting point.