Correlation of surface core levels and structural building blocks for the Si(111)-7×7 reconstruction through high-resolution core-level spectroscopy

The Si(111)-7×7 reconstruction is investigated by high-resolution core-level spectroscopy. A detailed line-shape analysis of spectra recorded over a wide photon energy range demonstrates the presence of four surface-derived components in the Si 2p line. These are attributed to the structural building blocks of the (7×7) structure through their relative intensities, evaluated for different photon energies in order to take photoelectron-diffraction effects into account, and on the basis of temperature-dependent changes in line shape that occur in the (7×7)-(1×1) phase transition at around 1130 K.