Berlin 2005 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

O: Oberflächenphysik

O 39: Nanostrukturen IV

O 39.2: Talk

Tuesday, March 8, 2005, 11:00–11:15, TU EB420

STM contrast between Ge and Si atoms incorporated in the Si(111)-√(3)× √(3)-Bi surface — •Josef Mysliveček, Neelima Paul, and Bert Voigtländer — Institut für Schichten und Grenzflächen (ISG 3) and cni - Center of Nanoelectronic Systems for Information Technology, Forschungszentrum Jülich, 52425 Jülich, Germany

The termination of the Si(111) surface by 1 ML Bi prevents intermixing between subsequently deposited Ge and Si atoms that incorporate below the Bi layer. At the same time, apparent height difference between the incorporated Ge and Si monolayers is observed in the scanning tunneling microscope, allowing the control of the formation of lateral Ge-Si nanostructures on the Si(111)-√(3)× √(3)-Bi surface. Using scanning tunneling spectroscopy techniques we study the origin of this apparent height difference. While the densities of electronic states measured over the incorporated Ge and Si layers do not differ significantly, a significant lowering of the inverse decay length is observed for the unoccupied electron states over the incorporated Ge layer. This indicates, that the presence of the incorporated Ge layer on the Si(111)-√(3)× √(3)-Bi surface decreases the electron affinity on this surface.