Structure, photoluminescence and thermoluminescence study of a composite ZnTa2O6/ZnGa2O4 compound doped with Pr3+

Abstract The study of persistent luminescence is interesting for applications related to biological imaging, self-lit roads and security signs. Composite Pr-doped samples were prepared in one pot by solid chemical reaction at 1200 °C for 4 h. The X-ray diffraction patterns of the samples showed mixed phases which correspond to ZnGa 2 O 4 and ZnTa 2 O 6 phases. Interestingly, the secondary electron microscopy images showed that the surface morphology is composed of particles with different shapes: irregular, rhombus and rod shapes. The X-ray maps obtained using field emission scanning electron microscopy, confirmed that the irregular particles correspond to ZnTa 2 O 6, and the rods correspond to ZnGa 2 O 4 . Red emission was observed from 1 D 2 → 3 H 4 , 3 P 0 → 3 H 6 , 3 P 0 → 3 F 2 and 1 D 2 → 3 H 5 transitions of Pr 3+ . The lifetime of the persistent luminescence was measured, and the corresponding trapping centres were investigated using thermoluminescence spectroscopy.