title: Origin of fine structure in si photoelectron spectra at silicon surfaces and interfaces.
abstract: Using a first-principles approach, we investigate the origin of the fine structure in Si 2p photoelectron spectra at the Si(100)-(2 x 1) surface and at the Si(100)-SiO2 interface. Calculated and measured shifts show very good agreement for both systems. By using maximally localized Wannier functions, we clearly identify the shifts resulting from the electronegativity of second-neighbor atoms. The other shifts are then found to be proportional to the average bond-length variation around the Si atom. Hence, in combination with accurate modeling, photoelectron spectroscopy can provide a direct measure of the strain field at the atomic scale.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne (EPFL), Institute of Chemical Sciences and Engineering, CH-1015 Lausanne, Switzerland.
authors.forename: Oleg V
authors.initials: OV
authors.lastname: Yazyev
authors.forename: Alfredo
authors.initials: A
authors.lastname: Pasquarello