Regensburg 2010 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 40: TR: Nanoelectronics III: Molecular Electronics 2
TT 40.4: Vortrag
Freitag, 26. März 2010, 11:45–12:15, H20
Electronic Transport Measurements on Si4 Clusters — •Jochen Grebing1,2, Rainer Dietsche1, Gerd Ganteför1, Thomas Kirchner1, and Elke Scheer1 — 1Department of Physics, University of Konstanz, D-77457 Konstanz, Germany — 2Forschungszentrum Dresden-Rossendorf, D-01328 Dresden, Germany
A still intriguing issue in the field of molecular electronics is the dependence of the transport properties of a molecule or cluster on the exact geometric realization of the contact at the atomic scale. Here, Si4 clusters come in handy as they have a very well known rhombohedral geometry as well as a limited yet diverse number of possibilities of being contacted.
After soft-landing from the gas phase, using a mechanically controlled breakjunction technique, possibly single or few Si4 clusters were contacted with atomically sharp tips and transport characteristics were measured. In addition to conductance histograms, current-voltage (IV) curves with and without clusters in the junction have been recorded. By comparison with the outcome of DFT calculations, the presence of the clusters could be identified in the histograms.
By fitting a resonant tunneling model to the IV curves, the coupling between the clusters and the leads as well as the energy difference of the molecular orbital contributing to the transport and the Fermi energy in the leads could be determined.
We thank F. Pauly for providing the DFT code and for introducing us to it’s use, A. Erbe and J. C. Cuevas for the introduction to the resonant tunneling model and valuable discussions.