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Molecular junctions based on aromatic coupling

Nature Nanotechnology volume 3, pages 569–574 (2008)Cite this article

Abstract

If individual molecules are to be used as building blocks for electronic devices, it will be essential to understand charge transport at the level of single molecules. Most existing experiments rely on the synthesis of functional rod-like molecules with chemical linker groups at both ends to provide strong, covalent anchoring to the source and drain contacts. This approach has proved very successful, providing quantitative measures of single-molecule conductance, and demonstrating rectification and switching at the single-molecule level. However, the influence of intermolecular interactions on the formation and operation of molecular junctions has been overlooked. Here we report the use of oligo-phenylene ethynylene molecules as a model system, and establish that molecular junctions can still form when one of the chemical linker groups is displaced or even fully removed. Our results demonstrate that aromatic π−π coupling between adjacent molecules is efficient enough to allow for the controlled formation of molecular bridges between nearby electrodes.

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Figure 1: Anchoring of a molecule in a metal junction.
Figure 2: Measurement apparatus and conductance curves.
Figure 3: Conductance histograms for the different molecules.
Figure 4: Illustration of possible stacking configurations.

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Acknowledgements

This work was financed by the Swiss National Science Foundation and the National Center of Competence in Research ‘Nanoscale Science’. We also acknowledge the GEBERT RU¨F STIFTUNG for financial support. M.T.G. acknowledges the ‘Ministerio de Educación y Ciencia’ and the Freiwillige Akademische Gesellschaft for financial support.

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Authors and Affiliations

  1. Department of Physics, University of Basel, Klingelbergstrasse. 82, Basel, CH-4056, Switzerland

    Songmei Wu, Maria Teresa González, Roman Huber, Christian Schönenberger & Michel Calame

  2. Department of Chemistry, University of Basel, St Johanns-Ring 19, Basel, CH-4056, Switzerland

    Sergio Grunder & Marcel Mayor

  3. Forschungszentrum Karlsruhe GmbH, Institute for Nanotechnology, PO Box 3640, Karlsruhe, D-76021, Germany

    Marcel Mayor

Authors
  1. Songmei Wu
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Contributions

S.W., R.H. and M.T.G. carried out the experiments and conducted the analysis; S.G. synthesized the molecules; M.C., M.M. and C.S. designed the experiment, initiated the collaboration and supported the project in discussions; and S.W., C.S. and M.C. wrote the manuscript.

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Correspondence to Marcel Mayor or Michel Calame.

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Wu, S., González, M., Huber, R. et al. Molecular junctions based on aromatic coupling. Nature Nanotech 3, 569–574 (2008). https://doi.org/10.1038/nnano.2008.237

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