Effect of Defect Distribution on the Optical Storage Properties of Strontium Gallates with a Low-Dimensional Chain Structure

The low-dimensional structure of the SrGa2O4 host exhibits a self-activated long persistent luminescence related to the creation of the oxygen vacancies. Because of the unique structure of the SrGa2O4 with a chain of cations along the a crystal direction, the emission and trapping centers could be introduced easily when the metal ions of Bi3+ are doped. Both the photoluminescence and long persistent luminescence are related to two efficient emission centers of Bi3+ in the two different crystallographic Sr sites, while the photostimulated luminescence spectra exhibit only one emission center of Bi1 ions under excitation at 980 or 808 nm. The results indicate that the distribution of defects in the low-chain structure of the SrGa2O4 host plays a vital role in the capture and transfer processes of carriers, which has a profound influence on the luminescence performance of SrGa2O4:Bi3+ as one of the electron-trapping materials.