Yellow persistent luminescence in Ce3+-Cr3+-codoped gadolinium aluminum gallium garnet transparent ceramics after blue-light excitation

We have developed a yellow persistent phosphor of Ce3+-Cr3+-codoped Gd3Al2Ga3O12 transparent ceramics prepared by a solid-state reaction. The yellow persistent luminescence due to the Ce3+: 5d-4f transition was observed even after 460 nm blue-light excitation as well as after UV excitation. The chromaticity coordinate of the persistent luminescence in the ceramic phosphor is located at (0.394, 0.557), which appears really yellow compared with the color coordinate of the well-known SrAl2O4:Eu2+-Dy3+ or other conventional blue or green persistent phosphors. The luminance values for the transparent ceramic sample 1, 5, and 30min after the blue excitation was ceased are 731, 63, and 8 mcd/m(2), respectively. (C) 2014 The Japan Society of Applied Physics