Scintillation and VUV-excited photoluminescence of europium-doped BaF₂–Al₂O₃–B₂O₃ glasses

We have investigated the X-ray induced luminescence (XRL) and the lifetime of a series of yEu₂O₃–50BaF₂–xAl₂O₃–(50-x)B₂O₃ (x = 0–25, y = 1–10, in mol%) glasses, which exhibit high PL quantum yields (Shinozaki et al. in Opt Mater 36:1384, 2014), for potential scintillator applications. In addition, the effects of Al₂O₃ content and dopant concentrations of Eu³⁺ ions used for quenching were particularly focused. The XRL intensity of the 25Al₂O₃ glass was 76% of that for the 0Al₂O₃ glass. The lifetime increased with increasing the concentration of Al₂O₃, and the XRL lifetime was shorter than the PL lifetime. Concentration quenching was also observed, where the PL intensity increased with increasing the concentration of Eu₂O₃ below y = 10. In addition, the 3Eu₂O₃-doped glass exhibited the highest XRL intensity among the materials tested. The mechanism underlying this behavior was discussed in comparison with conventional PL and VUV-excited PL spectroscopies.