Investigations of Ce~(3+) Co-Doped SbPO_4:Tb~(3+) Nano-Ribbons and Nanoparticles by Vibrational and Photoluminescence Spectroscopy

摘要

Nano-ribbons and very small nanoparticles (size 2-5 nm) of SbPO_4 doped with lanthanide ions (Ce~(3+) and Tb~(3+)) are prepared at a relatively low temperature of 120℃ based on a solution method. Detailed vibrational and luminescence studies on these samples establish that these lanthanide ions are incorporated at Sb~(3+) site of the SbPO_4 lattice. The excitation spectrum corresponding to the Tb~(3+) emission and the excited state lifetime of the ~5D_4 level of Tb~(3+) ions in the sample confirm the energy transfer from Ce~(3+) to Tb~(3+) ions in the SbPO_4 host. The extent of energy transfer from Ce~(3+) to Tb~(3+) in these samples is found to be around 60%. Dispersion of these nanomaterials in silica matrix effectively shields the lanthanide ions at the surface of the nano-ribbonsanoparticles from the stabilizing ligands resulting in the reduction in the vibronic quenching of the excited state. Our results show significant reduction in the surface contribution in the decay curve corresponding to the ~5D_4 level of the Tb~(3+) ions after incorporating the nano-ribbonsanoparticles in silica. These nanomaterials incorporated in silica matrix can have potential applications in bio-assays and bioimaging.