Photoluminescence enhancement of red-emitting GdVO4:Eu and YVO4:Eu phosphors by adding zinc

We synthesized the rare-earth activated R0.94-xEu0.06ZnxVO4 (R: Gd and Y; 0≤x≤0.08) phosphors with a spherical morphology and a smooth surface by the ultrasonic spray pyrolysis. The annealed R0.94-xEu0.06ZnxVO4 crystallized in the tetragonal zircon type structure, belonging to the space group of I41/amd. The incorporation of a small amount of Zn to R0.94Eu0.06VO4 improved the emission characteristics. The emission intensities of the Gd0.88Eu0.06Zn0.06VO4 and Y0.9Eu0.06Zn0.04VO4 phosphors at 619 nm were 72% and 21% stronger than those of the Gd0.94Eu0.06VO4 and Y0.94Eu0.06VO4 phosphors, respectively. We demonstrated that the addition of Zn to R0.94Eu0.06VO4 was quite effective for improving the photoluminescent properties.