Fabrication and characterizations of Cr3+‐doped ZnGa2O4 transparent ceramics with persistent luminescence

Abstract 0.5 at.% Cr:ZnGa 2 O 4 precursor was synthesized by the co‐precipitation method with nitrates as raw materials, using ammonium carbonate as the precipitant. Low‐agglomerated Cr:ZnGa 2 O 4 powders with an average particle size of 43 nm were obtained by calcining the precursor at 900℃ for 4 h. Using the powders as starting materials, 0.5 at.% Cr:ZnGa 2 O 4 ceramics with an average grain size of about 515 nm were prepared by presintering at 1150℃ for 5 h in air and HIP post‐treatment at 1100℃ for 3 h under 200 MPa Ar. The in‐line transmittance of 0.5 at.% Cr:ZnGa 2 O 4 ceramics with a thickness of 1.3 mm reaches 59.5% at the wavelength of 700 nm. The Cr:ZnGa 2 O 4 ceramics can be effectively excited by visible light and produce persistent luminescence at 700 nm. For Cr:ZnGa 2 O 4 transparent ceramics, the brightness of afterglow was larger than 0.32 mcd/m 2 after 30 min, which is far superior to that of Cr:ZnGa 2 O 4 persistent luminescence powders.