Optical properties of porous YVO4:Ln (Ln = Dy3+ and Tm3+) nanoplates obtained by the chemical co-precipitation method

The present research describes a simple low-temperature synthesis route for obtention of porous YVO4:Dy and YVO4:Tm nanoplates via a chemical co-precipitation method using commercially available Y2O3, NH4VO3, Tm2O3, Dy2O3 and ethylene glycol as the reacting precursors. To investigate the effect of heating temperatures on the pore size and morphology of nanoplates-like powders, the as-synthesized YVO4:Ln were thermally treated at 300 and 600 deg. C for 2 h which is much lower than that of the conventional preparation methods. The obtained samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescent (PL) spectroscopy. The photoluminescence measurement revealed that the luminescence intensity was significantly increased with increasing annealing temperature that causes increase of crystallinity and pore size of the porous nanoplates. From PL spectra, it was found that porous YVO4:Dy nanoplates have characteristic emission peaks due to the 4F9/2 → 6H13/2 and 4F9/2 → 6H15/2 emission transitions of Dy3+. The experimental results have showed that the host YVO4 transfers the adsorbed energy to thulium ions and strong blue emission at 475 nm assigned to 1G4 → 3H6 transition was observed.