Control of molecule-based transport for future molecular devices

Abstract

In this review, possibilities to modify intentionally the electronic transport properties ofmetal/molecule/metal devices (MMM devices) are discussed. Here especially theinfluence of the metal work function, the metal–molecule interface, the moleculedipole and different tunneling mechanisms are considered. A route to evaluate theeffective surface work function of metal–molecule systems is given and, basedon experimental results, an exemplary estimation is performed. The electrontransport across different metal–molecule interfaces is characterized by relatingtransmission coefficients extracted from experimentally derived molecular conductances,decay constants or tunneling barrier heights. Based on the reported results thetunneling decay constant can be assumed to be suitable to characterize intrinsicmolecular electron transport properties, while the nature of the metal–moleculecontacts is properly described by the transmission coefficient. A clear gradation oftransmission efficiencies of metal–anchoring group combinations can be given.