Processing effect on the luminescence and raman spectra of Gd1-xVO4:Eux3+ phosphors

Nano-sized Eu³⁺-activated Gd_1-xVO₄ phosphors were prepared via hydrothermal reaction coupled with the coprecipitation method at a low temperature (230 °C). The coprecipitation provided chemical homogeneity. However, it resulted in a low crystallinity and reduced emission and excitation characteristics. Raman study showed that Gd-O bond lengths changed in powders, depending on the level of crystallinity. The particle morphology was controlled using ethylenediaminetetra-acetic acid during the hydrothermal reaction. Particle shapes in the nano-size range affected the vibration of atoms in the lattice, changing photoluminescence properties.