Shape controlled synthesis, characterization and photoluminescence properties of YVO4:Dy3+/Eu3+ phosphors

Raisin-like, grape-like and box-like nanocrystalline samples of YVO4:Dy3+(2 at.wt%)/Eu3+(4 at.wt%) have been synthesized by different preparative routes. The raisin-like nanocrystalline sample has been synthesised by a facile hydrothermal process, whereas a surfactant-assisted synthesis led to the formation of grape-like and box-like nanocrystalline samples, under different reaction conditions. The resulting products were characterised by XRD, TEM, FTIR and photoluminescence spectroscopy. One significant outcome of the photoluminescence study involved a detailed observation of the variations in the relative intensity of the 5D0–7F2 transition with respect to the 5D0–7F1 transition of Eu3+ in YVO4:Eu3+, and the relative intensity of 4F9/2–6H13/2 transition with respect to the 4F9/2–6H15/2 transition of Dy3+ inYVO4:Dy3+. The observations in either case were subsequently explained on the basis of change in the local symmetry of the dopant ion, due to the change in the host morphology. The presented results strongly indicate that the local environment around the dopant ion changes with the change in the host morphology, which in turn influences the chromaticity of the prepared phosphors (both YVO4:Eu3+ and YVO4:Dy3+).