Synthesis, Microstructure and Photoluminescence Properties of Yttrium Orthovanadates: Influences of Silica Nano-Particles and Nano-Layers

In this investigation, firstly Eu3+ doped YVO4 phosphor was synthesized using solid state method. Then silica was coated on the surface of particles via sol-gel method. The XPS characterization confirmed the formation of Y–O–Si and V-O-Si bodings between YVO4:Eu3+ phosphor particle and SiO2 coating. In addition, it was found that although the amounts of added SiO2 were not remarkable, but it resulted in enhancement of emission intensity of the phosphors. Finally by employing ESR analysis, it was shown that surface oxygen vacancies, result in reduction of V5+ to the lower valence state of V4+.