Synthesis and Photoluminescence Properties of Sc<sub>0.88-x</sub>Lu<sub>0.05</sub>VO<sub>4</sub>:Eu<sup>3+</sup><sub>0.07</sub>,Bi<sup>3+</sup><sub>x</sub> Red Phosphor

Abstract

Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x(0≤x≤0.05) red phosphors were synthesized by solid state reaction at 1200°C for 3h. The structure, morphology and luminescence spectra of samples are investigated by X-ray diffraction (XRD), Scanning electron microscope (SEM) and fluorescence spectrophotometer, respectively. The samples doped with Eu3+, Lu3+ and Bi3+ maintain the body-centered tetragonal structure of ScVO4 and the morphology remains essentially unchanged with slight agglomeration. The excitation spectrum of Sc0.88-xLu0.05VO4:Eu3+0.07,Bi3+x emerged redshift and the excitation intensity increase within the near UV excitation (360-400nm). The optimum doping concentration of Bi3+ is 0.02(x value), and the maximum emission intensity of Sc0.86Lu0.05VO4:Eu3+0.07,Bi3+0.02 is higher than 88 % in comparison with Sc0.88Lu0.05VO4:Eu3+0.07 under 365 nm excitation. Decay curve of 5D0 state for as-prepared samples fits the single order exponential behavior, the lifetime of 5D0 increase first and then decrease with the increase of Bi3+ doping concentration. The internal quantum efficiency is up to 74.08% under 365nm excitation; When the temperature raises to 200°C, the emission intensity maintains 79% of that in the room temperature. Sc0.86Lu0.05VO4:Eu3+0.07,Bi3+0.02 phosphor show high internal quantum efficiency and thermal stability, which is suitable for the UV-pumped white LED as red phosphor.