| Thermoelectric effect has been widely studied,since Seebeck effect was first found in1823.However, due to restriction of Wiedemann-Franz law and Mott relation，the application range ofthe thermoelectric technology is limited to specific cases due to its low effciency. Owing toadvances in the nanotechnology, thermoelectric effect in nanostructures has attracted muchinterest in recent years due to the high efficiency of converting heat into electricity or viseversa.In the first chapter we briefly introduced the thermoelectric effect, the thermoelectric effectin nanomaterials, quantum dots,Fano effect, etc. In the second chapter we studied themicrowave-mediated heat transport in a quantum dot attached to leads. we found that when themicrowave is applied only on the QD and in the linear-response regime, the main peaks in thethermoelectric figure of merit and the thermopower are found to decrease, with the emergence ofa set of photon-induced peaks. Under this condition the microwave field can not generate heatcurrent or electrical bias voltage. Surprisingly, when the microwave field is applied only to one(bright) lead and not to the other (dark) lead or the QD, heat flows mostly from the dark to thebright lead, almost irrespectively to the direction of the thermal gradient. The microwave fieldcan change both the magnitude and the sign of the electrical bias voltage induced by thetemperature gradient.We studied the thermoelectric efficiency of parallel-coupled doublequantum dots (QDs) system in Chapter3. It is found that the configurations of the dot-leadcoupling strengths exert a significant impact on the figure of merit through the Fano effect,due towhich electrons experience an abrupt change from resonant to antiresonant tunneling.Theabsolute value of the thermopower is increased by the Fano resonance and antiresonance,whilethe electrical conductance is separately enhanced and suppressed,leading to the enhancement ofthe thermal efficiency of the device. |
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