Meny

Javascript verkar inte påslaget? - Vissa delar av Lunds universitets webbplats fungerar inte optimalt utan javascript, kontrollera din webbläsares inställningar.
Du är här

Bismuth-stabilized (2x1) and (2x4) reconstructions on GaAs(100) surfaces: Combined first-principles, photoemission, and scanning tunneling microscopy study

Författare:
  • M. P. J. Punkkinen
  • P. Laukkanen
  • H. -P. Komsa
  • M. Ahola-Tuomi
  • N. Rasanen
  • K. Kokko
  • M. Kuzmin
  • Johan Adell
  • Janusz Sadowski (Dr)
  • R. E. Perala
  • M. Ropo
  • T. T. Rantala
  • I. J. Vayrynen
  • M. Pessa
  • L. Vitos
  • J. Kollar
  • S. Mirbt
  • B. Johansson
Publiceringsår: 2008
Språk: Engelska
Sidor:
Publikation/Tidskrift/Serie: Physical Review B
Volym: 78
Nummer: 19
Dokumenttyp: Artikel
Förlag: American Physical Society

Sammanfattning

Bismuth adsorbate-stabilized (2x1) and (2x4) reconstructions of the GaAs(100) surfaces have been studied by first-principles calculations, valence-band and core-level photoelectron spectroscopies, and scanning tunneling microscopy. It is demonstrated that large Bi atom size leads to the formation of the pseudogap at the Fermi energy and to the lower energy of an adsorbate-derived surface band, which contributes to the stabilization of the exceptional Bi/GaAs(100)(2x1) reconstruction. It is proposed that the Bi/GaAs(100)(2x4) reconstructions include asymmetric mixed Bi-As dimers, in addition to the Bi-Bi dimers. Based on the calculations, we solve the atomic origins of the surface core-level shifts (SCLSs) of the Bi 5d photoemission spectra from the Bi/GaAs(100)(2x4) surfaces. This allows for resolving the puzzle related to the identification of two SCLS components often found in the measurements of the Bi 5d and Sb 4d core-level emissions of the Bi/III-V and Sb/III-V(100)(2x4) surfaces. Finally, the reason for the absence of the common (2x4)-beta 2 structure and additional support for the stability of the (2x1) structure on the Bi/III-V(100) surfaces are discussed in terms of Bi atom size and subsurface stress.

Disputation

Nyckelord

  • Physics and Astronomy
  • surface reconstruction
  • scanning tunnelling microscopy
  • spectra
  • photoelectron
  • III-V semiconductors
  • gallium arsenide
  • Fermi level
  • gap
  • energy
  • core levels
  • bismuth
  • ab initio calculations
  • adsorbed layers
  • valence bands

Övriga

Published
Yes
  • ISSN: 1098-0121

Box 117, 221 00 LUND
Telefon 046-222 00 00 (växel)
Telefax 046-222 47 20
lu [at] lu [dot] se

Fakturaadress: Box 188, 221 00 LUND
Organisationsnummer: 202100-3211
Om webbplatsen