The effect of Eu3+-activated InVO4 phosphors prepared by sol–gel method

Abstract

Indium orthovanadate (InVO4) doped with Eu3+ ions had been synthesized by sol–gel method. The precursor of InVO4:Eu3+ powders were heated at 950°C for 6h in air, and the crystal structure, surface morphologies and photoluminescence properties were also investigated. XRD patterns indicated that the crystallinity of InVO4:Eu3+ powders decreases with increasing Eu3+ ion concentrations. From the SEM micrographs, the shapes of the InVO4 particles are uniform and like pebbles. With increasing Eu3+ ion concentrations, the shapes of the InVO4:Eu3+ particles become smaller and irregular. In the PL studies, the sharp excitation peaks between 300 and 600nm correspond to the Eu3+ intra-4f transitions. Excitation at 326nm in terms of Eu3+ concentrations in (In1−xEux)VO4 powders shows that the (In1−xEux)VO4 phosphors display bright red luminescence at about 615nm belonging to the 5D0→7F2 electric dipole transition, and the time-resolved 5D0→7F2 transition presents a single exponential decay behavior. The concentration quenching is active when the Eu3+ concentration is larger than 30mol%, and the critical distance is about 8.024Å.