Core-level spectroscopy of the clean Si(001) surface: Charge transfer within asymmetric dimers of the 2×1 and <i>c</i>(4×2) reconstructions

Erik Landemark; C. J. Karlsson; Y.-C. Chao; R. I. G. Uhrberg

doi:10.1103/PhysRevLett.69.1588

Core-level spectroscopy of the clean Si(001) surface: Charge transfer within asymmetric dimers of the 2×1 and c(4×2) reconstructions

Erik Landemark, C. J. Karlsson, Y.-C. Chao, and R. I. G. Uhrberg

Phys. Rev. Lett. 69, 1588 – Published 7 September 1992

Abstract

Extremely well-resolved Si 2p core-level spectra have been obtained from the clean Si(001) surface. Spectra from the cold c(4×2) and the RT 2×1 surfaces are very similar, implying that the local structure of the two reconstructions is the same. Shifted components originating from both up and down atoms of asymmetric dimers, as well as second-layer atoms, are identified. The split of ∼0.55 eV between the two dimer-atom components points to a substantial charge transfer within the dimers. We find no support for the recently proposed crystal-field splitting of the surface components.