Bipolar Conductance Switching of Single Anthradithiophene Molecules
| Autor: | Klaus Kern, Hagen Klauk, Ivan Pentegov, Tomasz Michnowicz, Peter Wahl, Rémi Pétuya, Andrés Arnau, Verena Schendel, Bogdana Borca, Ulrike Kraft, Uta Schlickum |
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| Přispěvatelé: | Eusko Jaurlaritza, Ministry of Science, Research and Art Baden-Württemberg, German Research Foundation, Ministerio de Economía y Competitividad (España), University of St Andrews. School of Physics and Astronomy, University of St Andrews. Condensed Matter Physics |
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Bistability NDAS STM General Physics and Astronomy Nanotechnology DFT law.invention Pentacene symbols.namesake chemistry.chemical_compound law General Materials Science HOMO/LUMO QC Organic electronics Molecular switch Cu(111) Fermi level Conformational and electronic switching General Engineering QC Physics chemistry Chemical physics symbols Charge carrier cis/trans ADT isomers Scanning tunneling microscope |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1936-086X |
| Popis: | Single molecular switches are basic device elements in organic electronics. The pentacene analogue anthradithiophene (ADT) shows a fully reversible binary switching between different adsorption conformations on a metallic surface accompanied by a charge transfer. These transitions are activated locally in single molecules in a low-temperature scanning tunneling microscope . The switching induces changes between bistable orbital structures and energy level alignment at the interface. The most stable geometry, the “off” state, which all molecules adopt upon evaporation, corresponds to a short adsorption distance at which the electronic interactions of the acene rings bend the central part of the molecule toward the surface accompanied by a significant charge transfer from the metallic surface to the ADT molecules. This leads to a shift of the lowest unoccupied molecular orbital down to the Fermi level (EF). In the “on” state the molecule has a flat geometry at a larger distance from the surface; consequently the interaction is weaker, resulting in a negligible charge transfer with an orbital structure resembling the highest occupied molecular orbital when imaged close to EF. The potential barrier between these two states can be overcome reversibly by injecting charge carriers locally into individual molecules. Voltage-controlled current traces show a hysteresis characteristic of a bipolar switching behavior. The interpretation is supported by first-principles calculations. We acknowledge funding by the EmmyNoether-Program of the Deutsche Forschungsgemeinschaft, the SFB 767, and the Baden-Württemberg Stiftung. R.P. and A.A. thank the Basque Departamento de Universidades e Investigacion (grant no. IT-756-13) and the Spanish Ministerio de Economia y Competitividad (grant no. FIS2013-48286-C2-8752-P) for financial support. |
| Databáze: | OpenAIRE |
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