Thermoelectric transport through single molecule junctions

The charge and heat transport properties of single multilayered cyclophane stacks connected to gold electrodes are calculated in the framework of ab initio electronic structure calculations combined with non-equilibrium greens function techniques. The heat transport include both the electronic and phononic contribution, which allows a fully ab initio determination of the thermoelectric transport properties. We investigate the influence of the molecular length and of the molecule-electrode binding motif on the electron and phonon transport characteristics. We find that the power factor is limited due to the fact that the Wiedeman-Franz law remains approximate valid due to the strong off-resonant electron transport. On the other hand the large phonon mismatch between the molecule and the gold electrodes leads to a suppression of the phonon thermal conductance.