Lifetime of holes and electrons at metal surfaces; electron–phonon coupling

Surface chemical reactions are influenced by inherent dissipative processes which involve energy transfer between the conduction electrons and the ionic motion. We will discuss how it is possible to model this electron–phonon coupling in order to estimate its importance. A relevant quantity for this investigation is the lifetime of surface localized electron states. A surface state, quantum-well state or surface image state is located in a surface projected band gap and becomes relatively sharp in energy. This makes a comparison between calculations and experimental data most attractive, with a possibility to resolve the origin of the lifetime broadening. We point out the importance of taking into account the phonon spectrum, electron surface state wave functions and the screening of the electron–ion potential.We acknowledge partial support by the Basque Country Government, the University of the Basque Country, Ministerio de Ciencia y Tecnologia.Peer reviewe