Regensburg 2002 – wissenschaftliches Programm
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SYOH: Organische Halbleiter
SYOH 7: Poster
SYOH 7.19: Poster
Montag, 11. März 2002, 18:00–21:00, C
Electronic transport through occupied and unoccupied states of an organic molecule on Au: Experiment and Theory — •Michael Toerker1, Torsten Fritz1, Holger Proehl1, Rafael Gutierrez2, Frank Grossmann2, and Rüdiger Schmidt2 — 1Institut für Angewandte Photophysik, TU Dresden, 01062 Dresden — 2Institut für Theoretische Physik, TU Dresden, 01062 Dresden
Scanning tunneling spectroscopy (STS) measurements on highly ordered double layers of the planar organic molecule hexa-peri -hexabenzocoronene (C42H18) on Au(100) are presented and compared to a theoretical characterization of the electronic conductance based on a combination of the Landauer transport formalism with a density-functional-parametrized tight-binding scheme within the Local Density Approximation (LDA). Tunneling Spectroscopy data have been recorded within an extended voltage range of ±2.5 V. In this room temperature STS experiment it was possible to derive not only the energetic positions of the front orbitals of a molecular species from tunneling spectroscopy but also the energies of the molecular states next to these front orbitals. To achieve a satisfactory agreement between experiment and theory a scaling parameter is necessary which compensates the underestimation of the electronic energy gap in LDA.