Synthesis and Characterization of Core-Shell Silica-Phosphor Nanoparticles <italic>via</italic> Sol-Gel Process

Abstract

<p>Cost-effective functional phosphor nanoparticles are prepared by introducing low-cost SiO<sub>2</sub> spheres to rareearth phosphor (YVO<sub>4</sub>:Eu<sup>3+</sup>, YVO<sub>4</sub>:Er<sup>3+</sup>, and YVO<sub>4</sub>:Nd<sup>3+</sup>) shells using a sol-gel synthetic method. These functional nanoparticles are characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and general photoluminescence spectra. The SiO<sub>2</sub> sphere occupying the interior of the conventional phosphor is advantageous in significantly reducing the cost of expensive rare-earth phosphor nanoparticles. The sol-gel process facilitates the core–shell structure formation; the rare-earth shell phosphor has strong interactions with chelating agents on the surfaces of SiO<sub>2</sub> nanoparticles and thus forms layers of several nanometers in thickness. The photoluminescence wavelength is simply tuned by replacing the active materials of Eu<sup>3+</sup>, Er<sup>3+</sup>, and Nd<sup>3+</sup>. Moreover, the photoluminescent properties of the core–shell nanoparticles can be optimized by manipulating the specific contents of active materials in the phosphors. Our simple approach substitutes low-cost SiO<sub>2</sub> for expensive rare-earth-based phosphor materials to realize cost-effective phosphor nanoparticles for various applications.</p>