Red phosphorescence in Sr4Al14O25: Cr3+,Eu2+,Dy3+ through persistent energy transfer

Abstract

Cr 3 + , Eu 2 + , and Dy 3 + codoped Sr 4 Al 14 O 25 has been synthesized by solid-state reaction. Long persistent phosphorescence in red of Cr 3 + and in blue of Eu 2 + has been observed in this system with persistence times of over 2 h for the red and 10 h for the blue. Red phosphorescence is performed through persistent energy transfer from Eu 2 + to Cr 3 + , converting the blue to the red. Concentration effect is analyzed based on energy transfer. The calculated results are in good agreement with the experimental data. The different decay patterns of the red and blue phosphorescence are measured and discussed.