Near Infrared Luminescence Enhancement of Fe3+-Doped Mgga2o4 Phosphor by Li+-Assisted Oxygen Vacancy Repair Strategy

Fe3+-doped MgGa2O4 (MGO: Fe3+) spinel-type phosphors are promising near-infrared (NIR) luminescent materials because of its non-toxic, good thermal stability and adjustable emission. Unfortunately, the existence of detrimental oxygen defects in the MgGa2O4 host lead to unsatisfactory luminescence efficiency. In this study, an oxygen vacancy repairing engineering has been innovatively developed via Li+ substitution in MGO: Fe3+ for significantly enhancing NIR emission of 709 nm and maintaining outstanding thermal stability. The emission intensity and internal quantum efficiency of Li-repaired MGO: Fe3+ are enhanced to 130 % and 156% times compared to that of the MGO: Fe3+, respectively. This study demonstrates an innovative strategy to enhance the photoluminescence quantum yield of MgGa2O4-based infrared phosphors by reducing the oxygen vacancies through cation repair route.