Luminescence properties of LaPO4:Tb3+,Me3+ (Me = Gd, Bi, Ce) under VUV excitation

The luminescence properties of LaPO4:Tb3+,Me3+ (Me = Gd, Bi, Ce) were investigated under VUV excitation. The results indicate that only Gd3+ plays an intermediate role in energy transfer from the host absorption band to Tb3+ under 147 nm excitation, Bi3+ and Ce3+ have no contribution to improving the emission intensity of La0.95PO4:Tb0.053+ because the charge transfer band of Bi3+ is mismatching for the excitation wavelength (147 nm) and Ce3+ can be oxidized easily. A new band at 135 nm is observed in the excitation spectrum of La0.92PO4:Tb0.053+,Bi0.033+, which may correlate with the absorption of Bi2+.