Investigation of Ce-Mn Energy Transfer in SrAl2O4:Ce3+,Mn2+

Ce3+ and Mn2+ singly doped and codoped SrAl2O4 phosphors were prepared by the solid-state reaction. Ce3+- and Mn2+-codoped SrAl2O4 phosphor shows tunable blue to green emission. Apart from the emission band of Ce3+ at 374 nm, which ascribes to the site of Sr2+ occupied by Ce3+, the emission of Mn2+ located at 515 nm was also observed for the energy transferred from Ce3+ to Mn2+ in SrAl2O4:Ce3+,Mn2+. By appropriately tuning the activator content, the developed phosphors can generate lights from blue to green region. In addition, green phosphorescence from Mn2+ was observed in the codoped system, which was due to the persistent energy transfer between Ce3+ and Mn2+. The finding suggests a promising approach to controlling the color of the photoluminescence and phosphorescence of persistent phosphors.