Ce3+ to Mn2+ energy transfer in Sr3Y2Ge3O12:Ce3+, Mn2+ garnet phosphor

Ce3+ and Mn2+ singly doped and co-doped Sr3Y2Ge3O12 phosphors were synthesized by the solidestate reaction. In these phosphors Ce3+ ions occupy exclusively the Sr2+ site while Mn2+ ions mostly the Y3+ site with some traces in the Sr2+ site. Under excitation at 430 nm into the Ce3+ absorption band the Sr3Y2Ge3O12:Ce3+, Mn2+ phosphor emits green light from Ce3+ (530 nm) and red light from Mn2+ (630 nm) due to the Ce3+/Mn2+ energy transfer. By appropriate ratio of the active ion concentrations the Ce3+ and Mn2+ co-doped Sr3Y2Ge3O12 phosphor can generate lights from green to orange region. We showed that the mechanism of energy transfer from Ce3+ to Mn2+ is of the resonance type and it occurs via an electric dipoleedipole interaction. Furthermore, we calculated the critical distance for Ce3+/Mn2+ energy transfer to be 16.90 angstrom by concentration quenching methods. (C) 2015 Elsevier B.V. All rights reserved.