Thermoelectric effects of molecular quantum dot junctions with strong electron phonon interactions

We theoretically study the electrical conductance, thermal power, electron thermal conductance and figure of merit of a single molecular quantum dot junction using the Anderson model with a strong coupling of electron-phonon interactions (EPIs). The figure of merit (ZT) decreases with increasing strength of EPIs. The suppression of ZT is mainly attributed to a considerable enhancement of electron thermal conductance. We have demonstrated that the resolution of thermal power for resolving multiple phonon-assisted tunneling processes is higher than that of electrical conductance. Because the Kelvin relation is satisfied, the Peltier coefficient can also be determined by using measuring the thermal power.