Effect of Trisodium Citrate on the Morphology and Luminescence Properties of Hydrothermally Synthesized YVO₄ Phosphor

YVO₄ phosphors with different morphologies were synthesized by trisodium citrate (Na₃cit) surfactant-assisted hydrothermal process. Effects of molar ratio of $\text{cit}^{3-}$ to $Y^{3+}$ and pH value of reaction solution were intensively investigated on the morphologies, structures and luminescence properties of YVO₄ phosphor. The morphologies of the YVO₄ particles can be effectively controlled in strong acidic and strong alkaline environment by affecting the adsorption of $\text{cit}^{3-}$ on the (001) crystal plane of YVO₄. Strong acidic condition resulted into excessive adsorption of $\text{cit}^{3-}$ groups on the YVO₄ phosphor, which annihilated the superior luminescence of YVO₄ phosphors. On the contrary, strong alkaline condition does not result into the adsorption of $\text{cit}^{3-}$ groups. The synthesized YVO₄ phosphor without adsorption of $\text{cit}^{3-}$ groups showed superior luminescence even though the effective control of the morphology in alkaline condition is not so good as in strong acidic condition.