Preparation and upconversion luminescence of YVO4:Er3+, Yb3+

YVO4:Er3+, Yb3+ with varying Yb3+ concentrations were prepared by a precipitation method. The results of X-ray diffraction (XRD) show that all the samples have a tetragonal zircon structure; the calculated average crystallite sizes are in the range of 14-22 nm. The lattice constants and cell volume of the samples decrease slightly with the increase in Yb3+ concentration. The upconversion luminescence spectra of all the samples were studied under 980 nm laser excitation. The strong green emission is observed, which is attributed to the H-2(11/2)-> I-4(15/2) and S-4(3/2)-> I-4(15/2) transitions of Er3+, and the red emission peaks in 650-675 nm can be ignored. The emission intensity for the sample depends on the Yb3+ concentration. These results reveal that the upconversion processes of YVO4:Er3+, Yb3+ are related to the structure and the doping Yb3+ concentration of the sample.