Achieving Superior n/γ Discrimination and Luminescent Thermal Stability in Cs2LiLaBr6 Single Crystals by High Concentration Ce3+ Doping

In this work, a strategy of manipulating the cerium activator concentration was adopted to enhance the n/γ discrimination and luminescent thermal stability of Cs2LiLaBr6 (CLLB). CLLB single crystals doped different cerium concentrations with a size of Φ12 mm × 50 mm were grown by the Bridgman method. The crystal structure and actual concentration of Ce3+ were determined by the XRD and ICP-AES methods. The effects of cerium doping amount on the luminescence properties, thermo-stability, scintillation properties, and n/γ discrimination capability were systematically investigated. Compared with the low Ce3+ concentration doping (1 and 2 mol %), the higher concentration crystal (10 mol %) presents a better n/γ discrimination capability with a high figure-of-merit of 2.1, which is the optimum result for the CLLB:Ce crystal. It is important that the thermal quenching temperature T(50) of CLLB:10 mol % Ce crystal is higher than 460 K when the CLLB:1 % Ce crystal is about 340 K. It shows a potential application in the field of extreme environments.