Influence of Ag nanoparticles on luminescent performance of SiO2:Tb3 + nanomaterials

Tb3 + single-doped SiO2 (SiO2:Tb3 +) and Tb3 +, Ag co-doped SiO2 (SiO2:Tb3 +–Ag) nanostructured luminescent materials were prepared by a modified Stöber method. Their microstructure and optical property were investigated using scanning electron microscopy, ultraviolet visible absorption and photoluminescence spectrophotometry. Results show that the samples are composed of well-dispersed near-spherical particles with a diameter about 50 nm, the highest fluorescence intensity is obtained when the doping concentration of Tb3 + is 4.86 mol%, the corresponding internal quantum efficiency is 13.6% and the external quantum efficiency is 8.2%. The experimental results indicate that Ag nanoparticles can greatly enhance the light absorption at 226 nm and the light emission at 543 nm of SiO2:Tb3 +–Ag, and the fluorescence lifetime reduces with increasing Ag concentration in SiO2:Tb3 +–Ag. Additionally, the present results indicate that fluorescence enhancement is attributed to the local field enhancement and the increased radiative decay rates induced by Ag nanoparticles.

► SiO2:Tb3 + obtained highest intensity with Tb3 + content of 4.86 mol%.
► The emission intensity at 543 nm is enhanced by 35% after Ag nanoparticles doped.
► Absorption at 226 nm enhanced and fluorescence life time reduced at higher Ag content.
► The fluorescence enhancement and radiative decay rates increase caused by LSPR of Ag.