Electron Transport through Heterogeneous Intermolecular Tunnel Junctions

Quantum charge transport through intermolecular tunnel junctions is studied. Intermolecular tunnel junctions can be defined by the end groups of pairs of self-assembled monolayers of functionalized conjugated alkenes on gold surfaces. Conductivity dependence on the tunnel distance has been compared for various junctions. It is found that for junctions dominated by attractive interactions, for example, systems involving hydrogen bonding, conductivity exhibits less dependence on the tunneling distance than with junctions dominated by dispersive interactions. Junctions with stronger distance dependence conductivty are desired for applications related to chemical sensors. Our study provides insight for designing an efficient chemical sensor that is based on heterogeneous tunnel junction, which may involve conductivity through a combination of the attractive hydrogen-bonding channel and repulsive dispersive interactions.