Dresden 2011 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)

O 60.98: Poster

Mittwoch, 16. März 2011, 17:30–21:00, P4

Field Emission Resonances on the Quasi One-Dimensional Si(111)5x2-Au Reconstruction — •Stefan Polei, Ingo Barke, Kristian Sell, Viola von Oeynhausen, and Karl-Heinz Meiwes-Broer — Institut für Physik, Universität Rostock, D-18051, Rostock, Germany

Scanning tunnelling spectroscopy measurements of field emission resonances (FER) have shown to be a suitable tool to investigate local work function variations particularly on metal surfaces [1]. About FER on semiconductors or nanostructured surfaces less literature can be found. In this contribution we compare FER on different regions of a Si(111)7x7 substrate which is partially covered by the quasi one-dimensional Si(111)5x2-Au structure. Across a transition between Si(111)7x7 and Si(111)5x2-Au a shift of the FER peak positions is found which can be attributed to changes of the local work function. At increased spatial resolution dI/dV maps reveal a periodic shift of the higher order FER in the direction perpendicular to the chains of Si(111)5x2-Au. This effect appears on a length scale of less than one nanometer and is caused by surface-potential variations. Model calculations are shown to quantify their amplitude.

[1] T. Jung, Y. W. Mo, F. J. Himpsel, Phys. Rev. Lett. 74, 9 (1995).