Tuning the persistent luminescence property of a Y 3 Al 2 Ga 3 O 12 :Ce 3+ ,Yb 3+ phosphor by controlling the intrinsic oxygen vacancy concentration.

Oxygen vacancies (V _O ), acting as electron traps, have a significant impact on the persistent luminescence (PersL) property of persistent phosphors. However, the effect of V _O on PersL remains still unclear enough to limit the development of PersL materials. In this study, the V _O concentration of the Y _2.978 Ce _0.018 Yb _0.004 Al ₂ Ga ₃ O ₁₂ phosphor is accurately controlled by annealing in air and 10%H ₂ /90%Ar atmospheres at various temperatures. The results show as the annealing temperature increases during the air annealing the V _O concentration, the PersL durations, and the thermoluminescence (TL) intensity constantly decreases, and the three data coincide well with each other, indicating the PersL property of the Y _2.978 Ce _0.018 Yb _0.004 Al ₂ Ga ₃ O ₁₂ is successfully tuned. Besides, the trap structure of the Y _2.978 Ce _0.018 Yb _0.004 Al ₂ Ga ₃ O ₁₂ and the charge compensation effect of Yb ions on V _O defects are also discussed. By deconvoluting the TL curves, the Yb trap with a depth of 0.58 eV has been distinctly separated from the V _O traps with a quasi-continuous and broad distribution of depths ranging from 0.58 to 1.21 eV. Our work demonstrates a better understanding of the relationship between V _O and PersL is of great significance to design a high-performance phosphor.