Adsorbate-substrate charge transfer and electron-hole correlation at adsorbate/metal interfaces

The interaction and charge transfer at adsorbate/metal interfaces are studied with high-resolution core level and valence band photoelectron spectroscopy (PES) and near edge x-ray absorption fine structure spectroscopy. Various multilayer and monolayer films of different organic molecules on Ag(111) surfaces are investigated systematically. Distinct spectral features are observed in the PES spectra of the monolayer films which can be attributed to the interface interaction and charge transfer. Moreover, it is shown that these features are significant indications for the hybridization of adsorbate and substrate wave functions at the interface. This is related to a metallic character of the first adsorbate layer, which can be observed with various spectroscopic techniques.