Spectroscopy, thermoluminescence and afterglow studies of CaLa4(SiO4)3O:Ln (Ln=Ce, Nd, Eu, Tb, Dy)

The spectroscopic characterization down to 10 K was performed for undoped and Ln doped CaLa4(SiO4)3O (Ln=Eu3+, Eu2+, Ce3+, Dy3+, Tb3+). Based on the experimental and literature data the scheme was constructed showing the vacuum referred binding energy (VRBE) of electrons in lanthanide states and band states in CaLa4(SiO4)3O. This scheme predicts that co-doping with Eu2+ and Ln3+ (Ln=Dy, Nd) will induce afterglow. Thermoluminescence and afterglow were indeed measured and compared with a commercial SrAl2O4:Eu, Dy afterglow phosphor.