title: Conductance of a single conjugated polymer as a continuous function of its length.
abstract: 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.
authors.affiliation: Physics Department, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Leif
authors.initials: L
authors.lastname: Lafferentz
authors.forename: Francisco
authors.initials: F
authors.lastname: Ample
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.forename: Stefan
authors.initials: S
authors.lastname: Hecht
authors.forename: Christian
authors.initials: C
authors.lastname: Joachim
authors.forename: Leonhard
authors.initials: L
authors.lastname: Grill