Influence of co-doping different rare earth ions on the luminescence of CaAl2O4-based phosphors

CaAl2O4: Eu, RE3+ (RE: Dy, Nd, La) photoluminescent materials with high brightness and long afterglow are prepared by sintering at high temperature and in a reductive atmosphere. The influence of co-doping rare earth ions (Dy, La and Nd) on the luminescence of CaAl2O4: Eu was studied. The excitation and emission spectra of these three kinds of phosphors are very similar to that of CaAl2O4: Eu phosphor, and all of them have long afterglow phenomenon except for CaAl2O4: Eu. Both of initial brightness and persistent afterglow time of CaAl2O4: Eu, Nd is better than those of CaAl2O4: Eu, Dy, and CaAl2O4: Eu, La, which is agreement with the results of thermoluminescence curves. The low temperature photoluminescent spectra indicate that Eu ions occupied only one kind of Ca site in CaAl2O4 crystal lattice.