ELECTRONIC-STRUCTURE AND ITS DEPENDENCE ON LOCAL ORDER FOR H/SI(111)-(1X1) SURFACES

The valence and core level spectra of chemically prepared, ideally H-terminated Si(111) surfaces are characterized by remarkably sharp features. The valence band levels and their dispersion are well described by first-principles calculations using a quasiparticle self-energy approach within the GW approximation. From the Si2p spectra, an upper limit of 35 +/- 10 meV is derived for the core hole lifetime broadening, a value substantially lower than previously measured.