Cooperative energy transfer in Eu3+, Yb3+ codoped Y2O3 phosphor

Under 980 nm laser excitation, red emission (D-5(0)-F-7(J)(J=0, 1, 2)) of Eu3+ was observed in cubic Y2O3 codoped with Eu3+ and Yb3+. The dependence of the upconverted emission on doping concentration and laser power was studied. Yb3+ emission around 1000 nm (F-2(5/2)-F-2(7/2)) was reported upon excitation of Eu3+ ions. The decay curves of D-5(J) (J=0, 2) emission of Eu3+ under excitation of 266 nm pulse laser were examined to investigate the Eu3+-> Yb3+ energy transfer process. Cooperative energy transfer process was discussed as the possible mechanism for the visible up-conversion luminescence of Eu3+ and near-infrared down-conversion emission of Yb3+.