White light emission in Pr3+, Tb3+:CaYAlO4 phosphor

Abstract:

In this work, the synthesis and photoluminescence characteristics of two new phosphors Pr3+:CaYAlO4 (CYA) and Pr3+/Tb3+:CYA for light emitting diodes (LEDs) are investigated.0.5% (atom percentage) Pr3+:CYA exhibits the largest bright yellow emission by varying the Pr3+ concentration, owing to the cross-relaxation process of 3P0 +3H4→ 1G4+1G4. The energy level diagram in Pr3+:CYA, especially the positions of 4f5d level and 1S0 level, is discussed. By co-doping Tb3+ ions, the color coordinates of Pr3+/Tb3+:CYA phosphor can be tuned from yellow to white region. Finally, the strongest luminescence emission with color coordinates of (0.339, 0.364) located in the white region can be obtained in 0.3%Tb3+/0.5%Pr3+:CYA phosphor.