Dresden 2006 – wissenschaftliches Programm
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O: Oberflächenphysik
O 5: Electronic structure I
O 5.2: Vortrag
Montag, 27. März 2006, 11:30–11:45, WIL A317
Stark-Effect in STM induced Light Emission — •Germar Hoffmann1, Peter Johansson2, and Richard Berndt3 — 1Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, 20355 Hamburg,Germany — 2Department of Natural Sciences, University ofÖrebro, Sweden — 3IEAP, Christian-Albrechts-Universität zu Kiel,24098 Kiel
The tunnelling current in a scanning tunnelling microscope gives rise to the emission of photons. Owing to the small lateral dimension of the tunnelling current filament high lateral resolution can be achieved. The effect can be used for optical spectroscopy of nanoscale objects such as individual molecules. In STM induced light emission of Na layers on Cu(111) photon emission spectra reflect quantum well transitions. The energy of these transitions can be varied by the electric field of the tip, akin to a Stark effect. We will present experimental observations and numerical calculations for clean substrates, a number of Na coverages and various quantum well states. The results will be discussed in relation to recent observations of STM-induced molecular fluorescence.