In Situ Preparation and Luminescent Properties of CeF3 and CeF3:Tb~(3+) Nanoparticles and Transparent CeF3:Tb~(3+)/PMMA Nanocomposites in the Visible Spectral Range

摘要

CeF3 and CeF3:Tb~(3+) nanoparticles were prepared by reverse microemulsion with a functional monomer, methyl methacrylate (MMA), as the oil phase, and CeF3:Tb~(3+)/poly (methyl methacrylate) (PMMA) nanocomposites were obtained via polymerization of the MMA monomer. The nanoparticles and nanocomposites have been well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), low-and high-resolution transmission electron microscope (TEM), selected-area electron diffraction (SAED), thermogravimetric analysis (TGA), UV/vis transmission spectra, photoluminescence excitation, and emission spectra and luminescence decays. The well-crystallized CeF3 and CeF3:Tb~(3+) nanoparticles are spherical with a mean diameter of 15 nm. They show the characteristic emission of Ce~(3+) 5d-4f (313 nm, ~2D-~2F_(5/2);-323 nm, ~2D-~2F_(7/2)) and Tb~(3+) ~5D_4-~7F_J (J = 6-3, with ~5D_4-~7F_5 green emission at 541 nm as the strongest one) transitions, respectively. The energy transfer from Ce~(3+) to Tb~(3+) was investigated in CeF3:Tb~(3+) nanoparticles in detail. The obtained solid CeF3:Tb~(3+)/PMMA nanocomposites are highly transparent (in the visible spectral range) and exhibit strong green photoluminescence upon UV excitation, due to the integration of luminescent CeF3:Tb~(3+) nanoparticles. The luminescent lifetime of Tb~(3+) is determined to be 4.1 ms in the nanocomposite.