Preparation and characterization of sol–gel derived Er 3+–Yb 3+ codoped SiO 2/TiO 2 core–shell nanoparticles

Abstract

The Er 3+–Yb 3+ codoped silica/titania core–shell nanoparticles were prepared by hydrolysis of titanium alkoxide precursors in the presence of lanthanide ions via sol–gel method. The structure of the particles was characterized by field emission scanning electron microscopy and transmission electron microscopy. The diameter of the silica core is about 50 nm. The thickness of the titania shell is about 4 nm. A typical doping density of Er 3+ in the titania shell is 4.51 at.%, and the one of Yb 3+ is 12.20 at.%. The UV–vis–NIR absorption spectra and the photoluminescence spectra were also investigated.