Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 27 February 2009:
Vol. 323. no. 5918, pp. 1193 - 1197
DOI: 10.1126/science.1168255
Prev | Table of Contents | Next

Reports

Conductance of a Single Conjugated Polymer as a Continuous Function of Its Length

Leif Lafferentz,1 Francisco Ample,2 Hao Yu,3 Stefan Hecht,3 Christian Joachim,2 Leonhard Grill1*

The development of electronic devices at the single-molecule scale requires detailed understanding of charge transport through individual molecular wires. To characterize the electrical conductance, it is necessary to vary the length of a single molecular wire, contacted to two electrodes, in a controlled way. Such studies usually determine the conductance of a certain molecular species with one specific length. We measure the conductance and mechanical characteristics of a single polyfluorene wire by pulling it up from a Au(111) surface with the tip of a scanning tunneling microscope, thus continuously changing its length up to more than 20 nanometers. The conductance curves show not only an exponential decay but also characteristic oscillations as one molecular unit after another is detached from the surface during stretching.

1 Physics Department, Freie Universität Berlin, 14195 Berlin, Germany.
2 Nanosciences Group, Centre d'Elaboration des Materiaux et d'Etudes Structurales (CEMES)–CNRS, 31055 Toulouse, France.
3 Department of Chemistry, Humboldt-Universität zu Berlin, 12489 Berlin, Germany.

* To whom correspondence should be addressed. E-mail: leonhard.grill{at}physik.fu-berlin.de

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Novel Probes for Molecular Electronics.
E. Meyer and T. Glatzel (2009)
Science 324, 1397-1398
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)