Importance of surface states on the adsorption properties of noble metal surfaces

The Shockley-type surface state on noble metal (111) surfaces can be used as a sensitive probe for different surface modifications, adsorption processes, and interactions between adsorbate and substrate. On the model systems of Cu and Au(111) surfaces covered with noninteger monolayers of Ag we demonstrate that angle-resolved photoelectron spectroscopy is able to identify the growing positions of adsorbates by the investigation of the Shockley state. Vice versa, we discuss in a simple model to what extent the surface states themselves influence the adsorption process and determine the favored surface for physisorbed closed-shell systems.