Surface-site-selective study of valence electronic states of a clean Si(111)-7x7 surface using Si L{sub 23}VV Auger electron and Si 2p photoelectron coincidence measurements
- Department of Chemistry, Faculty of Science, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)
- Department of Physics, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)
- Institute of Materials Structure Science, Japan's National Laboratory for High Energy Physics (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan)
Valence electronic states of a clean Si(111)-7x7 surface are investigated in a surface-site-selective way using high-resolution coincidence measurements of Si pVV Auger electrons and Si 2p photoelectrons. The Si L{sub 23}VV Auger electron spectra measured in coincidence with energy-selected Si 2p photoelectrons show that the valence band at the highest density of states in the vicinity of the rest atoms is shifted by {approx}0.95 eV toward the Fermi level (E{sub F}) relative to that in the vicinity of the pedestal atoms (atoms directly bonded to the adatoms). The valence-band maximum in the vicinity of the rest atoms, on the other hand, is shown to be shifted by {approx}0.53 eV toward E{sub F} relative to that in the vicinity of the pedestal atoms. The Si 2p photoelectron spectra of Si(111)-7x7 measured in coincidence with energy-selected Si L{sub 23}VV Auger electrons identify the topmost surface components, and suggest that the dimers and the rest atoms are negatively charged while the pedestal atoms are positively charged. Furthermore, the Si 2p-Si L{sub 23}VV photoelectron Auger coincidence spectroscopy directly verifies that the adatom Si 2p component (usually denoted by C{sub 3}) is correlated with the surface state just below E{sub F} (usually denoted by S{sub 1}), as has been observed in previous angle-resolved photoelectron spectroscopy studies.
- OSTI ID:
- 21538062
- Journal Information:
- Physical Review. B, Condensed Matter and Materials Physics, Vol. 83, Issue 3; Other Information: DOI: 10.1103/PhysRevB.83.035320; (c) 2011 American Institute of Physics; ISSN 1098-0121
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ATOMS
AUGER ELECTRON SPECTROSCOPY
DENSITY
DIMERS
ELECTRONS
FERMI LEVEL
PHOTOELECTRON SPECTROSCOPY
RESOLUTION
SILICON
SURFACES
VALENCE
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
FERMIONS
LEPTONS
PHYSICAL PROPERTIES
SEMIMETALS
SPECTROSCOPY