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 <i>a</i> 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