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. (C) 2002 Published by Elsevier Science Ltd.