Erschienen:
American Association for the Advancement of Science (AAAS), 2009
Erschienen in:
Science, 323 (2009) 5918, Seite 1193-1197
Sprache:
Englisch
DOI:
10.1126/science.1168255
ISSN:
0036-8075;
1095-9203
Entstehung:
Anmerkungen:
Beschreibung:
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.