Crystal Growth and Luminescence Properties of Tm:BaF2 Single Crystals

BaF 2 is an intensively studied scintillator for the detection of gamma radiation due to its relatively high stopping power, radiation hardness and extremely fast response. BaF 2 possesses the fast cross-luminescence component at 195 and 220 nm with a lifetime of several hundred picoseconds. However, this component coexists with slow one at 310 nm related to the self-trapped exciton (STE). In our present study, we focused on BaF 2 host material and introduced the Tm 3+ (activator) 5d–4f vacuum ultraviolet (VUV) luminescence center to suppress the STE luminescence. Tm:BaF 2 single crystals were successfully grown by the micro-pulling-down (µ-PD) method with up to 10 mol % of Tm. The STE emission intensity decreased with increasing Tm concentration. Tm 3+ 5d–4f emission was observed while cross-luminescence was decreased at higher Tm concentrations.