Optical Properties of Cluster–Matter: Influences of Interfaces

Nanostructured material is characterized by its structuring interfaces. Cluster–matter, i.e. cluster/matrix systems, proved to be a well suited model system to study their electronic properties. The interactions between cluster and matrix induce structural and electronic effects which cause the interface to evolve into an extended interlayer. If the particles are metallic and develop a well defined optical Mie resonance, this resonance can be used to monitor electronic properties of the interlayer with high accuracy. In Part I (Section 2), after a short description of Mie's theory, two simple models concerning the static and the dynamic charge transfer are introduced. The first one results in an electric double-layer and changed conduction electron density in the cluster, while the second reduces, by phase relaxation, the lifetime of the Mie resonance. Both effects bear information about the electronic adsorbate states in the interlayer. In Part II (Section 3), data from the experimental investigation of a broad field of novel cluster–matter systems based on Ag-clusters are presented and a discussion closes the talk.