Correlation of afterglow, trap states and site preference in RE2O3:1%Eu (RE = Lu, Y, Sc) single crystal scintillators

RE2O3:1%Eu (RE=Lu, Y, Sc) single crystals were grown by the optical floating zone method. Correlated measurements of afterglow curves, thermoluminescence, photoluminescence decay, and radioluminescence curves were performed. It is found that the afterglow intensity of Sc2O3:Eu is much lower than the other two compounds and Y2O3:Eu presents a slightly lower afterglow intensity than Lu2O3:Eu. It is discussed in the light of the influence of trap states and site preference in the RE2O3:Eu. The afterglow difference between Sc2O3:Eu and other two compounds mainly comes from the disappearance of Schottky defect in Sc2O3:Eu. Meanwhile the afterglow difference between Y2O3:Eu and Lu2O3:Eu probably ascribes to the lower S6 site ratio in Y2O3:Eu. Their photoluminescence and other radioluminescence properties were also measured and compared.