Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

O: Oberflächenphysik

O 40: Halbleiteroberflächen und -grenzflächen

O 40.5: Vortrag

Donnerstag, 11. März 2004, 16:45–17:00, H45

Importance of carrier dynamics and conservation of momentum in atom-selective STM imaging of semiconductor surfaces — •Philipp Ebert¹, Nikos Jäger¹, Eicke Weber², and Knut Urban¹ — ¹Institut für Festkörperforschung, Forschungszentrum Jülich, 52425 Jülich — ²University of California and Lawrence Berkeley National Laboratory

Scanning tunneling microscopy and spectroscopy measurements on the GaAs(110) surface with complementary theoretical calculations are performed to clarify the effects involved in the tunneling of unpinned semiconductor surfaces. We show that the flatband and tip-induced band bending as well as equilibrium conditions are insufficient to describe the effects involved. Instead, carrier dynamics and conservation of momentum of the tunneling electrons need to be taken into account for a complete description of the contributions of the valence or conduction band states. The results allow us to understand the unique properties needed to achieve the atom-selective imaging on semiconductor surfaces as well as the determination of the band gap energy.