Synthesis and photoluminescence properties of (La, Pr) co-doped InVO4 phosphor

Abstract

(La3+, Pr3+) co-doped InVO4 phosphors were prepared using a sol–gel method. For the (In1−xPrx)VO4 (x=0–0.1) system, X-ray powder diffraction (XRD) patterns show that all of the peaks are attributed to the orthorhombic phase, and the scanning electron microscopy (SEM) images show that there is no obvious difference for the particle morphology between various Pr3+ ions doping. No emission peak characteristics of Pr3+ ions were observed under an excitation of 326nm. In the (In0.97−yLayPr0.03)VO4 (y=0–0.97) system, XRD patterns indicated that the crystal structure changed from the orthorhombic InVO4 structure to the monoclinic LaVO4 structure when the In3+ ions were gradually substituted by the La3+ ions. The location of excitation peaks shifted to short wavelength area (blue shift), and the characteristic f–f transition of Pr3+ ion was observed. With increasing La3+ ion concentration, a series of emission peaks assigned to the 3P0→3H4,5,6, 1D2→3H4, and 3P0→3F2 characteristic transitions of Pr3+ ion were observed in the emission spectra under an excitation of 315nm, and this indicated that the La3+ ion can act as a sensitizer for the (In0.97−yLayPr0.03)VO4 phosphor. The Commission Internationale de I'Eclairage (CIE) color chromaticity coordinates of (In0.97−yLayPr0.03)VO4 phosphors vary with the La3+ ion concentration from the yellowish light region, though the green-yellow and finally to the near-white light area as the La3+ ion concentration increased.