Photoluminescence properties of Y_0.75-xGd_xAl_0.10BO₃:Eu³⁺_0.10, 0.05R³⁺ (R = Sc, Bi) (0.00≤x≤0.45)

Y_0.75 - xGd_xAl_0.10BO₃:Eu^3+_0.10, 0.05R³⁺ (R = Sc, Bi) (0.00 ≤ x ≤ 0.45) powder samples are prepared by solid-state reaction and their luminescence properties are investigated. With the replacement of Y³⁺ ions by Sc³⁺ (or Bi³⁺) and Gd³⁺ ions in (Y, Al)BO₃:Eu, the intensities of emission at 254 and 147~nm are remarkably improved, because Sc³⁺ ions can absorb UV light and transfer the energy to Eu³⁺ ions efficiently. Moreover, Gd³⁺ and Bi³⁺ ions act as an intermediate ``bridge'' between the sensitizer and the activator (Eu³⁺) in energy transfer to produce light in the (Y, Gd)BO₃:Bi³⁺, Eu³⁺ system more effectively. After doping an appropriate concentration of Gd³⁺ into Y_0.50Gd_0.25Al_0.10BO₃:Eu^3+_0.01, Bi^3+_0.05, the emission intensity reaches its maximum, which is nearly 110\% compared with the red commercial phosphor (Y,Gd)BO₃:Eu and better chromaticity coordinates (0.650, 0.350) are obtained.