Key Words:Shells (structures);Emission spectroscopy - Fourier transform infrared spectroscopy - High resolution transmission electron microscopy - Phosphors - Photoluminescence - Precipitation (chemical) - Scanning electron microscopy - Silica - Transmission electron microscopy - X ray diffraction;Core shell - Energy dispersive x-ray - Fourier transform infra red (FTIR) spectroscopy - Hydrothermal methods - Luminescent property - Narrow size distributions - Photoluminescence spectrum - Precipitation methods
Abstract:SiO<inf>2</inf>@Y<inf>2</inf>O<inf>3</inf>:Eu<sup>3+</sup>spherical particles with core-shell structure have been synthesized successfully by a hydrothermal method, followed heat treatment, leading to the formation of monodisperse SiO<inf>2</inf>@Y<inf>2</inf>O<inf>3</inf>:Eu<sup>3+</sup>core-shell particles. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectra (EDS), transmission electron microscopy (TEM), Fourier Transform infrared spectroscopy (FT-IR) and photoluminescence spectra (PL) were used to characterize the as-obtained samples. The SEM indicates that the as-obtained core-shell particles show good spherical shape and non-agglomeration with a narrow size distribution (average size of 420 nm). Further studies about some experimental conditions show that the PL intensity is the highest when Y<inf>2</inf>O<inf>3</inf>:Eu<sup>3+</sup>layers are coated on the surface of SiO<inf>2</inf>particles with average size of about 150 nm annealed at 800 °C. For comparison, the core-shell particles are also synthesized by a simple precipitation method. The PL shows that under the excitation at 240 nm, the samples present strong red emission corresponding to the<sup>5</sup>D<inf>0</inf>→<sup>7</sup>F<inf>2</inf>transition of the Eu<sup>3+</sup>ions at 613 nm. Moreover, the emission spectra intensity by hydrothermal method is much higher than that of sample by precipitation method, because the former present the better dispersion, less percentage of the interface, and more thickness shells than that of the latter.<br/> © 2015 Elsevier B.V. All rights reserved.
Volume:46
Issue:期
Translation or Not:no
