Preparation of YVO₄:Eu³⁺ at low temperature by the hydrolytic sol–gel methodology

This work reports on the use of vanadium and yttrium alkoxides to prepare YVO₄ doped with the europium (III) ion and assesses the influence of basic catalysts on the photoluminescence properties of the resulting material. The obtained powder was treated at different temperatures, namely 100, 400, 600, and 800 °C, for 4 h. The XRD patterns revealed the formation of a YVO₄ crystalline phase for the samples prepared with and without the catalyst, regardless of the heat-treatment temperature. The excitation spectra of the samples treated at different temperatures displayed the charge transfer band at high energy ascribed to the transition from the vanadate to the europium (III) ion. The emission spectra exhibited the characteristic transition bands arising from the excited level ⁵D₀ to manifolds ⁷F_J (J = 0, 1, 2, 3, and 4), when the sample was excited at the charge transfer band and at the ⁵L₆ level of europium (III). The lifetime increased as a function of the temperature; it was higher than those reported for other samples prepared by other methodologies. The TEM micrographs evidenced cubic nanoparticles. Therefore, the sol–gel methodology affords YVO₄:Eu³⁺ phosphors.