Performance Optimization Analysis Of Three-terminal Quantum Dot Hybrid Thermoelectric Devices

In this thesis,three kinds of three-terminal quantum dot hybrid thermoelectric devices are studied.The analytical expressions of the performance parameters of thermoelectric devices under steady state are derived.The parameters are optimized to improve the performance of thermoelectric devices.This thesis is mainly divided into the following contents:In chapter 1,we introduce the difference between traditional thermoelectric devices and quantum thermoelectric devices,and the influence of photons and phonons on the performance of quantum thermoelectric devices.Then expound the research methods of quantum thermoelectric devices.In chapter 2,the model of photon-driven three-terminal heat engine is proposed,and the expressions of the electrical current and the heat absorbed from the photon terminal are obtained by using master equation and the basic thermodynamic formula.The performance of heat engine under non-strong coupling case is compared with one under strong coupling case.In chapter 3,the model of a three-terminal quantum dot thermoelectric refrigerator is established,which is constructed by two single-level quantum dots coupled with two electronic terminals and a photon terminal respectively.Based on stochastic master equation the expressions of the cooling power and the coefficient of performance(COP)are derived.The working regions are determined by the energy conservation and the second law of thermodynamics.The performance characteristic curves between the cooling power and the COP are plotted by numerical calculation.The influence of the positions of energy levels,the chemical potentials,and the nonradiative effects on the optimal performance parameters is discussed in detail.In chapter 4,we study the photon-driven refrigerator which consists of two twolevel quantum dots coupled with two electronic terminals.To give better guidance to the design and operation of the practical refrigerator,we consider the individual transitions in quantum dots.And we compare the performance characteristics of the refrigerator under the tight-coupling condition with that under the non-tight-coupling condition.The influence of the temperature of left terminal on the optimal performance parameters is discussed in detail.In chapter 5,we summarize the main research content and indicate the deficiency of this thesis.