Study on Long Persistent Luminescence Mechanism of Eu~(2+), Dy~(3+)- co-activated Strontium Aluminate Phosphors

The long persistent luminescence mechanism of phosphors based on Eu~(2+), Dy~(3+)-co-activated strontium aluminates was investigated in this paper. The recombination process of excited electron and hole produces luminescence (fluorescence). The process of thermal release and recombination of trapped holes and trapped electrons produces the long persistent phosphorescence. The incorporation of Dy~(3+) in Eu~(2+)-activated strontium aluminate phosphors creates not only hole traps but also electron traps with suitable depth, and makes the phosphors have stronger and longer lasting luminescence.