ESPCI web site
Jeudi 4 Avril 2013, 14h
Amphi Howleck, Esc C, 1ème etage
Probing inelastic charge transport through carbon based nanostructures
Ingmar Swart
Debye Institute for Nanomaterials Science, Utrecht University, Utrecht, the Netherlands
Electronic devices with organic molecules and other carbon based nanostructures as the basic building blocks have been proposed. In these systems the electrons are much more spatially confined as compared to inorganic semiconductors, leading to a much stronger electron-phonon (e-ph) coupling. Since this inelastic transport channel gives rise to substantial energy dissipation, it should be minimized in electronic devices.
In my talk, I will present two studies into inelastic charge transport through molecules relevant for molecular electronics. The first part deals with transport through molecules weakly coupled to the leads. It will be shown that even for an effective single-level system the energy dissipation associated with electron attachment varies spatially. This is in contrast to the usual treatment of e-ph coupling in the Franck-Condon picture. The origin of this spatial variation can be traced back to the local symmetry of initial and final wave function.
In the second part of the talk, I will show how contacting an atomically well-defined graphene nanoribbon (GNR) to a metallic lead by a chemical bond via only one atom significantly influences the charge transport through the GNR but does not affect its electronic structure. Specifically, we find that creating well-defined contacts can suppress inelastic transport.