Nanocomposite Er-Ag silicate glasses

Particular attention has being given to metal-dielectric nanostructured materials, due to the well known surface plasmon resonance, described as the oscillation of the free electrons with respect to the ionic background of the nanoparticle when they are collectively excited by laser irradiation. It is claimed that metal nanoparticles can be used for increasing the intensity of the luminescence emitted by rare earth ions. This effect is attributed to the strong absorption cross section related to the surface plasmon excitation in noble-metal nanoparticles and/or to the large local field enhancement generated around the excited nanoparticles. In spite of the large amount of work published on this topic, the mechanism of optical amplification remains controversial. Here we present x-ray photoelectron spectra and transmission electron images together with photoluminescence absorption and emission measurements, with the aim of providing a better understanding of the effective role of silver as a sensitizer for erbium.