Electronic states induced by surface defects on GaSb(110)

Electronic state calculations for point defects on the GaSb(110) surface are presented using a cluster, in order to indicate theoretically the usefulness of the defect model as a mechanism of the Fermi level pinning in Schottky barriers. The results demonstrate that the presence of atomic Ga at surface Sb vacancy sites in addition to surface Ga vacancies gives electronic states localized near the top of the valence band which can be responsible for the pinning observed experimentally.