Persistent luminescent and photocatalytic properties of ZnxGa2O3+x (0.8 ≤ x ≤ 1) phosphors

Abstract

The Zn_xGa₂O_3+x (x = 1, 0.95, 0.9, 0.85, 0.8) phosphors were synthesised successfully via high temperature solid-state reaction. The photoluminescent, persistent luminescent and photocatalytic properties of the phosphors had been studied systematically. The results indicated that their excitation and emission spectra were similar to those of ZnGa₂O₄ phosphors and all of them have excellent persistent luminescent and photocatalytic properties. The optical properties were changed with the ratio of the Zn²⁺/Ga³⁺ and the Zn_0.85Ga₂O_3.85 phosphor showed the best persistent luminescent and photocatalytic properties. The Zn_0.85Ga₂O_3.85 phosphor can be effectively activated by an ultraviolet lamp and ultraviolet excitation can lead to 10 min of persistent green emission. Moreover, the Zn_0.85Ga₂O_3.85 could provide more defect energy levels which can act as photogenerated electron traps and maintain the electron–hole pairs for a longer period, enhancing the persistent luminescent and photocatalytic performance.