Insights into the microscopic mechanism of persistent luminescence in Cr 3+ -doped ZnGa 2 O 4 phosphors

The origin of strong Cr 3+ PersL in Ga-based phosphors were elucidated. The results show that Cr 3+ substitution tunes the position of defect energy levels and enhances the anisotropy of its physical parameters, thereby enhancing PersL performance.