Nanocomposite Er-Ag Silicate Glasses

Particular attention has being devoted 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 the enhancement of the luminescence intensity 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 that is generated around the excited nanoparticle. In spite of the consistent number of published works on this topic, the mechanism of optical amplification still remains controversial. Here we present X-ray photoelectron spectroscopy, transmission electron microscope together with photoluminescence absorption and emission measurements with the aim of better understanding the effective role of silver as a sensitizer for erbium.