Charge Transport in Molecular Junctions

Self-energy-corrected transport calculations on single molecules between gold contacts explain the first simultaneous measurements of conductance and thermopower.

In collaboration with the Venkataraman group at Columbia University, we study junctions of individual amine- and pyradine-based molecules trapped between gold contacts. The Columbia group developed a novel setup based on a scanning-tunneling microscope to vary temperature and electrical biases while the molecules remain trapped, allowing them to simultaneously measure conductivity and thermopower.

Comparison of the experimental results to our charge transport calculations reveals an unexpectedly complex relationship between conductance and thermopower arising from chemical details of the metal-molecule contact, not the simple relation usually assumed. These findings critically advance knowledge of molecular-level charge transport, laying the groundwork for molecular-scale engineering of thermoelectric and other energy conversion materials.

Published in Nano Letters, 2012. link

Read more about our work on Molecular Junctions.