Sedghi, Gita and Garcia-Suarez, Victor M. and Esdaile, Louisa J. and Anderson, Harry L. and Lambert, Colin J. and Martin, Santiago and Bethell, Donald and Higgins, Simon J. and Elliott, Martin and Bennett, Neil and Macdonald, J. Emyr and Nichols, Richard J. (2011) Long-range electron tunnelling in oligo-porphyrin molecular wires. Nature Nanotechnology, 6 (8). pp. 517-523. ISSN 1748-3387
Full text not available from this repository.Abstract
Short chains of porphyrin molecules can mediate electron transport over distances as long as 5-10 nm with low attenuation. This means that porphyrin-based molecular wires could be useful in nanoelectronic and photovoltaic devices, but the mechanisms responsible for charge transport in single oligo-porphyrin wires have not yet been established. Here, based on electrical measurements of single-molecule junctions, we show that the conductance of the oligo-porphyrin wires has a strong dependence on temperature, and a weak dependence on the length of the wire. Although it is widely accepted that such behaviour is a signature of a thermally assisted incoherent ( hopping) mechanism, density functional theory calculations and an accompanying analytical model strongly suggest that the observed temperature and length dependence is consistent with phase-coherent tunnelling through the whole molecular junction.