Multiterminal single-molecule-graphene-nanoribbon junctions with the thermoelectric figure of merit optimized via evanescent mode transport and gate voltage

We propose thermoelectric devices where a single molecule is connected to two metallic zigzag graphene nanoribbons (ZGNRs) via highly transparent contacts that allow the injection of evanescent wave functions from ZGNRs. Their overlap generates a peak in the electronic transmission that is largely insensitive to the type of the short conjugated molecule, while ZGNRs additionally suppress hole-like contributions to the thermopower.

Thus optimized thermopower, together with suppression of phonon transport through a ZGNR-molecule-ZGNR structure, yields the thermoelectric figure of merit ZT similar to 0.5 at room temperature and 0.5