Study On Thermodynamic Performance Optimization Of Quantum Dot Thermoelectric Devices

Both the increasing consumption of energy and the waste of energy are the main problems during the human development,and how to efficiently use the wasted energy has become an effective way to solve the energy problem.At present,the trend of miniaturization and integration of electronic devices is obvious,and high-density electronic components produce lots of waste heat,but solid-state thermoelectric devices based on nanomaterials can convert this waste heat into electrical energy for use,which can thus dissipate heat from electronic components efficiently.As a typical nanomaterial,quantum dots are ideal candidates for the fabrication of micro-thermoelectric conversion devices(including thermoelectric heat generators and refrigerating machines).Based on the introduction of relevant research background in chapter 1,the main research contents of this paper are as follows:(1)We propose a single quantum dot(QD)heat engine triggered by a thermal bias(35)T and a voltage difference(35)?,where a circularly polarized light is applied on the QD region,and study the effect of system parameters on thermodynamic performances of the QD heat engine in the linear response regime.Moreover,the relevant physical mechanisms are elucidated.It is found that radiation light can effectively improve the output power and efficiency of the QD heat engine,furthermore,a reasonably good thermodynamic performance can be achieved by suitably adjusting system parameters,which mostly results from the violation of the Wiedemann-Franz law.(2)A double quantum-dot heat engine is proposed to explore how the ubiquitous quantum inference effects influence thermodynamic characteristics within the nonlinear response regime.We find that the quantum inference effect determines the magnitudes of power and efficiency in some sense,and reducing the quantum interference can enhance power and efficiency.But a detailed analysis of the double quantum-dot heat engine operating in the physically allowed parameters show that one can still obtain the substantial power output and efficiency,even the efficiency is in excess of 80% of the Carnot limit.The QD thermoelectric heat engine which has unique advantages in thermoelectric conversion is a typical energy conversion system.This paper mainly studies how some important factors influence(such as light field,magnetic field,Coulomb interaction,the quantum coherence,etc.)the thermodynamic performance of two typical QD thermoelectric engines.The research results provide effectivemeans for tuning optimizing thermodynamic performances of microscopic thermoelectric engines,which is of practical significance for designing and constructing of nanoscale thermoelectric engines.This thesis contains 29 figures and 113 references.