Controlled fabrication and shape-dependent luminescence properties of hexagonal NaCeF_4, NaCeF_4:Tb~(3+) nanorods via polyol-mediated solvothermal route

摘要

Hexagonal monodisperse NaCeF_4 and NaCeF_4:Tb ~(3+) nanorods have been successfully synthesized by a polyolmediated solvothermal route with ethylene glycol (EG) as solvent. The crystalline phase, size, morphology, and luminescence properties were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectra as well as dynamic decays. The experimental results indicate that the content of NH4F and NaNO_3 are crucial in controlling product morphology and size. Nanorods with different aspect ratios could be controllably obtained under settled conditions. Shape-dependent luminescence and energy transfer routes from Ce~(3+) to Tb~(3+) in NaCeF_4:Tb~(3+) nanorods were observed by the modified local crystal field environment around rare earth ions. The 4f-5d transitions of Ce~(3+) ions have much higher sensitivity to the anisotropic shape of samples than that of Tb~(3+) ions.