Luminescence and site occupancies of Eu3+ in La2CaB10O19

Eu3+-activated La2CaB10O19 phosphors with nominal chemical formulae La2−xEuxCaB10O19 and La2Ca1−2xEuxNaxB10O19 were prepared. The luminescence properties under VUV-UV excitation were investigated. Luminescence spectra reveal Eu3+ ions occupy both Ca2+ and La3+ sites in all samples. The O2− → Eu3+ charge transfer bands (CTBs) and the 5D0 → 7F0 emissions of Eu3+ at Ca 2+ site and La3+ site are identified, respectively. The schematic energy levels for Eu3+ in two sites were achieved. Luminescence decays of the 5D0 → 7F0 transitions were measured for both sites.