title: Molecular junctions based on aromatic coupling.
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 pi-pi coupling between adjacent molecules is efficient enough to allow for the controlled formation of molecular bridges between nearby electrodes.
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse. 82, CH-4056 Basel, Switzerland.
authors.forename: Songmei
authors.initials: S
authors.lastname: Wu
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: González
authors.forename: Roman
authors.initials: R
authors.lastname: Huber
authors.forename: Sergio
authors.initials: S
authors.lastname: Grunder
authors.forename: Marcel
authors.initials: M
authors.lastname: Mayor
authors.forename: Christian
authors.initials: C
authors.lastname: Schönenberger
authors.forename: Michel
authors.initials: M
authors.lastname: Calame
mesh_terms: D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D008956:Models, Chemical; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers; C473966:poly(phenylene ethynylene)