Preparation and luminescence properties of Ca2+-doped LaVO4:Dy3+ phosphors

LaVO4:Dy3+phosphors with and without Ca2+ doping (La1-x-y(DyxCay)VO4) were prepared by high temperature solid phase method, and their luminescence characteristics were studied. The luminescence performance of LaVO4 phosphor is the best when Dy3+ doping concentration is 0.05. Significant improvements in photoluminescence of LaVO4:Dy3+ phosphors were observed by Ca2+ doping. When the doping concentration of Ca2+ is 0.08, the luminescence performance of LaVO4 phosphor is the best. The Ca2+ ions incorporation increases the intensity of the Dy3+ ions luminescence. The underlying mechanisms of these results were calculated and investigated using first principles. The research shows that Ca2+ doping reduces the band gap value of LaVO4: Dy3+, resulting in the energy level splitting of Dy-d orbital, and the single atomic orbital shifts to higher energy direction after Ca2+ doping. First-principles calculations predict that calcium doping reduces the bandgap, resulting in matrix sensitization and an increase in luminescence intensity. Theoretical calculation results explain the improvement effect of Ca2+ doping on the luminescence properties of LaVO4:Dy3+ and reveal the mechanism.