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[摘要]：Monodisperse, well-defined, and photoluminescent CeF(3), CeF(3):Tb(3+), and CeF(3):Tb(3+)@LaF(3) core/shell nanocrystals (NCs) with small particle sizes (< 15 nm) have been successfully synthesized by a high-temperature thermolysis in high boiling solvent of oleic acid (OA) and 1-octadecene (ODE). The morphology, phase, composition, and the fluorescent properties of the as-synthesized samples were well characterized by means of transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), photoluminescence (PL) spectra, and kinetic decays, respectively. It is found that the as-synthesized NCs consist of monodisperse nanoparticles with narrow size distribution, which can easily disperse in nonpolar cyclohexane solvent to form transparent colloid solutions. The CeF(3), CeF(3):Tb(3+) and CeF(3):Tb(3+)@LaF(3) colloidal solutions show the characteristic emissions of Ce(3+) 5d-4f (353 nm) and Tb(3+) 5D(4) -> 7F(J) (J = 6-3) transitions, respectively. The growth of the LaF(3) shell on the CeF(3):Tb(3+) core NCs not only results in an increase of the average size, but significantly enhances the emission intensity and lifetime of the CeF(3):Tb(3+)@LaF(3) core/shell NCs with respect to those of CeF(3):Tb(3+) core NCs. Moreover, a transparent and fluorescent NCs/polydimethylsiloxane (PDMS) composite with regular dimension was also prepared by an in situ polymerization route. |
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