Hydrothermal synthesis and upconversion luminescent properties of YVO4:Yb3+,Er3+ nanoparticles

In this paper, YVO4:Yb3+,Er3+ nanoparticles have been successfully prepared via a facile hydrothermal technique in the presence of citric acid as a complexing agent followed by a subsequent heat treatment process. The nanostructures, morphologies and upconversion luminescent properties of the as-prepared YVO4:Yb3+,Er3+ upconverting nanoparticles were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescent (PL) spectra. XRD results indicate that all the diffraction peaks of samples can be well indexed to the tetragonal phase of YVO4. TEM images demonstrate that the samples synthesized hydrothermally consist of granular-like nanoparticles ranging in size from about 30 to 50 nm. After being calcined at 500-800 degrees C for 2 h, the grain sizes of nanoparticles increase slightly. Additionally, the as-prepared nanoparticles show bright green luminescence corresponding to the H-2(11/2) -> I-4(15/2) and S-4(3/2) -> I-4(15/2) transitions of Er3+ ions under the excitation of a 980 nm diode laser, which might find potential applications in fields such as phosphor powders, infrared detection and display devices. Crown Copyright (C) 2012 Published by Elsevier B. V. All rights reserved.