Roles of crystal defects in the persistent luminescence of Eu2+, Dy3+ co-doped strontium aluminate based phosphors

The roles of different point defects in persistent luminescence of SrAl2O4:Eu, Dy phosphors were investigated. The research results showed that Dy*Sr plays an important role in the persistent luminescence of SrAl2O4:Eu, Dy phosphors. It can serve as the electron trap of suitable depth for persistent luminescence. Vö does not serve as the electron trap of suitable depth, but its existence can increase the depth of electron traps. There is interaction between the Dy3+(Dy*Sr) and the Eu2+(Eu*sr), and only if the distance between the Dy3+(Dy*sr) and the Eu2+(Eu*Sr) is close enough, the Dy*Sr) can work as an effective electron trap. The point defect of V″Sr can be hole trap, but the change of its density in crystal matrix does not arouse the obvious change of persistent luminescence.