Berlin 2012 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 32: Transport: Nanoelectronics III - Molecular Electronics 1
TT 32.3: Vortrag
Mittwoch, 28. März 2012, 15:30–15:45, BH 334
Molecular orbital switching in photochromic single molecular junctions — •Youngsang Kim1, Torsten Pietsch1, Elke Scheer1, Thomas Hellmuth2, Fabian Pauly2, Dmitro Sysoiev3, Thomas Huhn3, Thomas Exner3, Ulrich Groth3, Ulrich Steiner3, and Artur Erbe4 — 1Department of Physics, Universität Konstanz, 78467 Konstanz, Germany — 2Institut für Theoretische Festkörperphysik, Karlsruhe Institute of Technology, 76131 Karlsruhe, Germany — 3Department of Chemistry, Universität Konstanz, 78467 Konstanz, Germany — 4Helmholtz-Zentrum Dresden Rossendorf, 01328 Dresden, Germany
Photoswitchable molecules gain significant interest due to the applicability in data storage media, as optical switches, and in novel logic circuits [1]. The molecular energy levels and their coupling to the metal electrodes determine both the single-molecule conductance and the switching ratio between the two states of a switch molecule. Here, we show the preferential conductance of individual, specifically designed sulfur-free diarylethene [2] molecules bridging mechanically controlled break-junction (MCBJ) electrodes at low temperatures. These molecules undergo a ring-opening/ring closure transition upon irradiation with light of suitable wave-length. We discuss the changes of molecular energy levels and electrode couplings in both isomers obtained by evaluating the current-voltage (I-V) characteristics using the single-level model [3].
M. Del Valle etal., Nat Nanotechnol 2, 176 (2007).
D. Sysoiev etal., Chem. Eur. J. 17, 6663 (2011).
Y. Kim etal., Nano Lett. 11, 3734 (2011); L. Zotti et al., Small 6, 1529 (2010).