Performance Optimization Analysis Of Three-terminal Multi-level Quantum Dot Thermoelectric Devices

In this thesis,the thermodynamic performance and performance optimization of two kinds of three-terminal multi-level quantum dot thermoelectric models are analyzed.Based on the theory of thermodynamics,the current and heat flow in the model are derived,and their power and performance coefficients are defined.Finally,some thermodynamic parameters are optimized to improve the performance by using these formulas we derive.The specific contents are as follows:In chapter 1,we introduce the research background of thermoelectric device and discuss the theory of the master equation and the Landauer formula.In chapter 2,a model of three-terminal multi-level quantum dot thermal amplifier with two symmetrical configurations is presented.The expressions of currents and heat fluxes which flow from the electronic terms,the heat-pumping rate and the coefficient of performance are obtained by using the theory of Landauer,as well as the working area of the thermal amplifier.We finally consider the influence of the number of energy levels,the energy-level spacing,the heat leakage,the asymmetric factor on the thermodynamic performance and optimize the performance of the thermal amplifier.And the influence of these parameters on the heat-pumping rate and the coefficient of performance of the thermal amplification are plotted.We also get the maximum heat-pumping rate,the maximum coefficient of performance and their correlative coefficient and rate under the consideration of these parameters.In chapter 3,a photon-driven three-terminal quantum dot refrigerator is proposed.The expressions of the cooling rate and coefficient of performance are derived by using the theory of master equation.We discuss the influence of energy level spacing and the asymmetric factor on the performance of the refrigerator in detail.Finally,we carry out the relevant performance optimization and obtain the optimization parameters under the maximum cooling rate and the maximum coefficient of performance.In chapter 4,we summarize the above work and give the direction of improvement.