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. (C) 2010 The Japan Society of Applied Physics
