Tuning the persistent luminescence property of a YAlGaO:Ce,Yb phosphor by controlling the intrinsic oxygen vacancy concentration.

Oxygen vacancies (V), acting as electron traps, have a significant impact on the persistent luminescence (PersL) property of persistent phosphors. However, the effect of V on PersL remains still unclear enough to limit the development of PersL materials. In this study, the V concentration of the YCeYbAlGaO phosphor is accurately controlled by annealing in air and 10%H/90%Ar atmospheres at various temperatures. The results show as the annealing temperature increases during the air annealing the V 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 YCeYbAlGaO is successfully tuned. Besides, the trap structure of the YCeYbAlGaO and the charge compensation effect of Yb ions on V 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 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 and PersL is of great significance to design a high-performance phosphor.