Characterizations of Pr3+ Ion-Doped LaVO4 Phosphor Prepared Using a Sol-Gel Method

The luminescent properties of Pr3+ ion-doped LaVO4 phosphor synthesized by the sol-gel method were investigated. The x-ray powder diffractometry results shows that the crystal structure of LaVO4 doped with Pr3+ phosphor calcined at 950 degrees C for 6h can be attributed to the monoclinic structure of LaVO4. There are no obvious differences for surface morphologies of La1-xPrxVO4 phosphors from the SEM results. For Pr3+ ion-doped LaVO4 phosphor, the O2- and V5+ charge transfer for the VO43- internal anion overlaps the 4f-5d characteristics transition of Pr3+ ion at the absorption band of 315nm. There are some emission bands that exist in the emission spectra, which are attributed to the (P0H4,5,6)-P-3-H-3, (D2H4)-D-1-H-3, and (P0F2)-P-3-F-3 electron transition of the Pr3+ ion under an excitation wavelength of 315nm. However, the intensity of emission peak at 607nm is stronger than that of 489nm when the Pr3+ concentration is less than 2mol.%. The Commission Internationale de I'Edairage (CIE) chromaticity coordinates from an orange-red shift to a white light region and then shift to a light-green region.