Dependence of Ce3+ - related photo- and thermally stimulated luminescence characteristics on Mgt(2+) content in single crystals and epitaxial films of Gd-3(Ga,Al)(5)O-12:Ce,Mg
Abstract
Photoluminescence and thermally stimulated luminescence of Gd-3(Ga,Al)(5)O-12:Ce single crystals and epitaxial films co-doped with different concentrations of Mg2+ ions are investigated in the 77-500 K temperature range under excitation in the 4f - 5d(1) and 4f - 5d(2) absorption bands of Ce3+ ions. Influence of Mg2+ ions on the photoluminescence intensity, spectrum, decay kinetics, temperature dependence of the photoluminescence intensity, and the activation energy of luminescence thermal quenching is observed.
Co-doping with Mg2+ is shown to result in a drastic reduction of the afterglow and thermally stimulated luminescence and in a strong shortening of the afterglow decay kinetics. It influences also defects creation spectra and the activation energy of the photostimulated defects creation.
The Mg2+ - induced changes in the characteristics of the Gd-3(Ga,Al)(5)O-12:Ce, Mg single crystals and epitaxial films are found to be strongly different, and possible reasons of these differences are discussed.