Fermi-level pinning and surface-state band structure of the Si(111)-(√3×√3)<i>R</i>30°-Ag surface

L. S. O. Johansson; E. Landemark; C. J. Karlsson; R. I. G. Uhrberg

doi:10.1103/PhysRevLett.63.2092

Fermi-level pinning and surface-state band structure of the Si(111)-(√3×√3)R30°-Ag surface

L. S. O. Johansson, E. Landemark, C. J. Karlsson, and R. I. G. Uhrberg

Phys. Rev. Lett. 63, 2092 – Published 6 November 1989

Abstract

The surface-state band structure and symmetry properties of the Si(111)-(√3 × √3) R30°-Ag surface have been studied with polarization-dependent, angle-resolved photoemission. In contradiction to the prevailing picture of this surface, we find an intrinsic, dispersive surface-state band in the bulk band gap. The minimum of this band is located 0.1 eV above the valence-band maximum ( $E_{V}$ ), and the observed partial occupation of the band determines the Fermi-level position (0.2 eV above $E_{V}$ ) on this surface.