Effects of interdot hopping and Coulomb blockade on the thermoelectric properties of serially coupled quantum dots
1 Department of Electrical Engineering and Department of Physics, National Central University, Chungli, 320, Taiwan
2 Research Center for Applied Sciences, Academic Sinica, Taipei, 115, Taiwan
Nanoscale Research Letters 2012, 7:257 doi:10.1186/1556-276X-7-257Published: 16 May 2012
We have theoretically studied the thermoelectric properties of serially coupled quantum dots (SCQDs) embedded in an insulator connected to metallic electrodes. In the framework of Keldysh Green’s function technique, the Landauer formula of transmission factor is obtained using the equation of motion method. Based on such analytical expressions of charge and heat currents, we calculate the electrical conductance, Seebeck coefficient, electron thermal conductance, and figure of merit (ZT) of SCQDs in the linear response regime. The effects of interdot hopping and electron Coulomb interactions on ZT are analyzed. We demonstrate that ZT is not a monotonic increasing function of interdot electron hopping strength (tc). We also show that in the absence of phonon thermal conductance, SCQD can reach the Carnot efficiency as tcapproaches zero.