ABSTRACT
Using angle-resolved photoelectron spectroscopy we investigate the electronic valence band structure of the Si(331)-(12 × 1) surface reconstruction for which we recently proposed a structural model containing silicon pentamers as elementary structural building blocks. We find that this surface, reported to be metallic in a previous study, shows a clear band gap at the Fermi energy, indicating semiconducting behavior. An occupied surface state, presumably containing several spectral components, is found centered at - 0.6 eV exhibiting a flat energy dispersion. These results are confirmed by scanning tunneling spectroscopy and are consistent with recent first-principles calculations for our structural model.
Subject(s)
Electrons , Microscopy, Scanning Tunneling/methods , Quantum Dots , Silicon/chemistry , Electron Transport , Image Processing, Computer-Assisted/methods , Photoelectron Spectroscopy/methods , Surface PropertiesABSTRACT
A new structural model for the Si(331)-(12x1) surface reconstruction is proposed. Based on scanning tunneling microscopy images of unprecedented resolution, low-energy electron diffraction data, and first-principles total-energy calculations, we demonstrate that the reconstructed Si(331) surface shares the same elementary building blocks as the Si(110)-(16x2) surface, establishing the pentamer as a universal building block for complex silicon surface reconstructions.
ABSTRACT
Driven by the reduction of dangling bonds and the minimization of surface stress, reconstruction of silicon surfaces leads to a striking diversity of outcomes. Despite this variety even very elaborate structures are generally comprised of a small number of structural building blocks. We here identify important elementary building blocks and discuss their integration into the structural models as well as their impact on the electronic structure of the surface.