Electronic structure and its dependence on local order for H/Si(111)-(1×1) 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 [ital GW] approximation. From the Si[sub 2[ital p]] spectra, an upper limit of 35[plus minus]10 meV is derived from the core hole lifetime broadening, a value substantially lower than previously measured.