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Jeudi 28 Mars 2013, 14h
Amphi Howleck, Esc C, 1ème etage
Electronic transport in molecular junctions and junctions networks
Michel Calame
Department of Physics and Swiss Nanoscience Institute, University of Basel, Switzerland
Nanometer scale structures embedding molecular compounds represent a versatile test-bed to
investigate non-equilibrium quantum transport phenomena. We follow two experimental routes to
characterize and control electronic transport in molecular junctions.
Using atomic contacts prepared with a mechanically-controllable break junction system, we
investigate the electro-mechanical properties of individual molecular junctions. Operating these
devices in a liquid environment, we have for instance observed the importance of intermolecular
interactions and stacking effects [1]. Molecular junctions are not static devices and undergo
dynamical reconfigurations. By acquiring IV characteristics at a relatively high rate, we can follow
the time evolution of the junctions and gain insight in the various geometries explored and their
electronic properties. Conducting AFM further provides the possibility to simultaneously
investigate the electrical and mechanical properties of Au-Au and Au-molecule-Au junctions [2].
Using Au nanoparticle arrays as a backbone structure, we investigate the transport properties of
molecular junctions networks. We have demonstrated that this platform can be efficiently used to
study transport modulation effects via chemical [3] and optical [4] stimuli as well as study
photoconductance effects [5].
[1] S. Wu et al., Nature Nano., 3, 569-574 (2008)
[2] C. Nef et al., Nanotechnology, 23, 365201 (2012)
[3] J. Liao, et al., Nano Letters, 10 (3), 759–764 (2010)
[4] S. van der Molen, et al., Nano Letters, 9 , 76-80 (2009)
[5] M. A. Mangold et al., ACS Nano, 6 (5) , 4181–4189 (2012)