Effect of Sm3+co-doping on the luminescence behavior of Pr3+-activated Sr3Al2O6 orange-reddish phosphors

The luminescence properties of Sr3Al2O6:Pr3+ flower-like materials were effectively improved by co-doping Sm3+ ions. The co-dopant of Sm3+/Pr3+ produces the defects of VO center dot center dot, Pr center dot Sr, Pr center dot center dot Sr and Sm center dot Sr, as well as the defect clusters of [Pr center dot Sr-O''i-Pr center dot Sr]/[Pr center dot center dot Sr-O'' i-Pr center dot center dot Sr]/[Sm center dot Sr-O''i-Sm center dot Sr] in the material lattices. The prepared phosphors have the effective trap depths of 0.76 eV and 0.78 eV with significantly high trap concentrations due to the introduction of Sm3+, enhancing the ability of defects' capturing carriers, and extending the life span of electron-hole pairs in lattices, which greatly improves the luminescence properties of the materials. Based on the energy band theory and defect theory, the luminescence mechanism of Sm3+ co-doped long afterglow materials was established.