Fabrication and long persistent luminescence of Ce3+-Cr3+ co-doped yttrium aluminum gallium garnet transparent ceramics

Persistent luminescence (PersL) materials are widely used in safety indication, traffic and transportation signs, architectural decoration and other fields. In this paper, (Y 1‒ x Ce x ) 3 (Al 0.9995 Cr 0.0005 ) 2 Ga 3 O 12 ( x =0.001, 0.002, 0.003, 0.005) transparent ceramics were successfully prepared by solid-state reaction method in air followed by HIP post-treatment. With the increase of Ce 3+ doping concentration, the optical quality of the as-prepared ceramics was improved and the morphology was denser. Luminescent quenching occurs when the Ce 3+ concentration was more than 0.2%. The as-prepared transparent ceramics were annealed in different atmospheres. From the PersL decay curves, the transparent ceramics after air annealing show the best PersL performance: luminance with 4424.0 mcd/m 2 and PersL duration over 865 min after ceasing 365 nm excitation, respectively. The effects of Ce 3+ doping concentration and annealing atmospheres are also discussed in detail. The YAGG:Ce 3+ ,Cr 3+ persistent luminescence (PersL) ceramics show excellent green PersL performance after the removal of excitation source. The PersL mechanism is discussed based on the electron trapping and de-trapping process.