Enhanced red emission on co-doping of divalent ions (M2+ = Ca2+, Sr2+, Ba2+) in YVO4:Eu3+ phosphor and spectroscopic analysis for its application in display devices

This paper reports the enhancement in photoluminescence due to the alkaline ions (M2+) co-doping in YVO4:Eu-3+ phosphors prepared by solid state reaction method. The as synthesized samples were found to have single phase tetragonal structure and the incorporation of dopant/codopant did not affect the crystal structure. The characteristic bands of Y-O and V O were located at 450 cm(-1) and 830 cm-1, respectively. The microscopic images exhibited the irregular morphology of the synthesized phosphor consisting of urn sized particles. Upon UV excitations, all phosphors showed intense red-orange emissions corresponding to the D-5(0) -> F-7(J1,2):Eu3+:Eu3+ transitions, and the emission intensity was further enhanced due to codoping. Divalent ions introduced radiative defect centers, which enhances the PL intensity significantly. The calculation of spectral parameters was done through Judd-Ofelt theory from emission spectra. The photometric characterizations and corresponding calculations indicated the suitability of the phosphor for display devices. (C) 2015 Elsevier B.V. All rights reserved.