Fabrication and characterization of the MgGa 2 O 4 transparent ceramic with multicolor persistent luminescence

The MgGa 2 O 4 transparent ceramic was fabricated using pressureless sintering combined with hot isostatic pressing. The obtained ceramic exhibited an in‐line transmittance of 64.5% at 0.7 µm and 81.6% at 2.5 µm. Three emission peaks at the wavelength of 430, 503, and 706 nm were observed in both photoluminescence and long persistent luminescence processes of the MgGa 2 O 4 transparent ceramic for the first time, owing to the behavior of the intrinsic defects. It was found that the transparent ceramic had ∼100 times brighter initial afterglow and ∼15 times longer persistent duration than MgGa 2 O 4 powder. In addition, the afterglow color of transparent ceramic changed from blue to green after ceasing the excitation source for 5 min, due to which the blue persistent luminescence originated from the rapid release of electrons trapped by shallow traps via CB. However, the weak but long‐lasting afterglow with green emission was generated by the slow tunneling of electrons to the corresponding luminescence centers.