Shape controlled synthesis, characterization and photoluminescence properties of YVO 4:Dy 3+/Eu 3+ phosphors

Abstract

Raisin-like, grape-like and box-like nanocrystalline samples of YVO 4:Dy 3+(2 at.wt%)/Eu 3+(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 5D 0– 7F 2 transition with respect to the 5D 0– 7F 1 transition of Eu 3+ in YVO 4:Eu 3+, and the relative intensity of 4F 9/2– 6H 13/2 transition with respect to the 4F 9/2– 6H 15/2 transition of Dy 3+ inYVO 4:Dy 3+. 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 YVO 4:Eu 3+ and YVO 4:Dy 3+).