Near-Infrared to Visible Up-Conversion Luminescence Characteristics of Er, Yb Co-Doped LaVO₄ Phosphors.

Er3+ and Yb3+ co-doped LaVO4 phosphors were synthesized by the facile solid state reaction method. Er3+ ions concentrations were changed from 0.01 to 0.2 mol for the fixed Yb3+ ions concentration at 0.15 mol. The crystalline structures of the phosphors were investigated by X-ray diffraction (XRD). The composition of the phosphors were investigated by X-ray photoelectron spectroscopy (XPS) analysis. The photoluminescence emissions based on the blue emission near 466 nm and green emission near 553 nm were observed and the highest emission intensity occurred for the sample LaVO4:Yb0.15, Er0.20. The green and red up-conversion emissions were observed in Er3+, Yb3+ co-doped LaVO4 phosphors under the excitation of 980 nm laser diode. LaVO3:Yb3+, Er3+ phosphors could be utilized to produce green colored LEDs by excitation for infra-red LED.