Facile Mixed-Solvent-Thermal Synthesis and Characterization of Shape-Controlled Monodisperse CeF_3:Tb~(3+) Nanocrystals

摘要

Monodisperse CeF_3:Tb~(3+) nanocrystals have been synthesized from mixed solvents-thermal synthesis under mild condition. The products have been characterized by High Resolution Transmission electron microscopy (HRTEM), X-ray diffraction (XRD), UV-visible Diffuse Reflectance spectra and luminescent spectra, respectively. Besides, different solvents ratio and different surfactants to synthesize CeF_3:Tb~(3+) nanocrystals have been compared to investigate the influence on their microstructure and morphology. As a result, the HRTEM images reveal the products crystallize in the hexagonal structure corresponding to the XRD and illustrate the mean rod length of about 15 nm, whose preferred orientation is parallel to the growth direction, namely c axis direction. The solvent ratios have influence on the microstructure and morphology of the products to some extent. With the increase of DMF solvent, the shape of CeF_3:10%Tb~(3+) changed from grain-like particles to rodlike ones. In addition, a disordered array of CeF_3:10%Tb~(3+) nanocrystals can be obtained with the existence of oleic acid. The characteristic emissions of Tb~(3+) originated from ~5D_4 →~7F_J (J = 6,5,4,3) are observed, and the dominant peak was the green emission of 543 nm. Measurements of emission spectra have been performed to examine the effect of Tb~(3+) concentration quenching on spectroscopic properties. The optimum doping-concentration ratio of Tb~(3+) was found to be approximately 15 mol%.