【作者】 刘伟；

【导师】 白龙；

【作者基本信息】 中国矿业大学 ， 凝聚态物理， 2020， 硕士

【摘要】 能源消耗的日益增长和能源浪费是当前人类发展面临的主要问题,如何有效利用浪费的能源已经成为解决能源问题的一条有效途径。当前,电子器件的小型化和集成化趋势明显,高密度的电子元件产生大量的废热。但利用纳米材料设计的固态热电器件能够将这些废热转变为电能加以利用,这也能够对电子元件进行有效的散热。量子点作为一种典型纳米材料成为制备微观热电转换装置(包括热电热机和制冷机)的理想候选者。本文在第1章介绍相关研究背景的基础上,主要开展的研究内容如下:(1)考虑了一个由温度差(35)T和化学势差(35)?驱动的单量子点热电热机模型,用圆偏振光照射中心量子点区域,在线性响应下,详细讨论了系统参数对量子点热机热力学性能的影响,并阐述了其中的物理机制。研究发现辐射光可以有效的提高输出热机的功率和效率,通过适当地调节参数可以使热电器件获得较好的热力学性能,其主要原因是微观热电转换器件违反了魏德曼-弗兰兹定律。(2)考虑了一个双量子点热电热机模型,在非线性响应下研究了微观热电器件中普遍存在的量子相干性对热力学性能系数的影响。研究发现量子干涉效应在某种程度上决定了功率和效率的大小,量子干涉的减小能够增强功率和效率。对双量子点热机在物理参数允许的空间内的详细分析表明:在量子干涉效应的影响下仍然有机会获得一个实质性的输出功率和效率,甚至效率可以达到卡诺效率的80%以上。量子点热电热机是典型的能量转换系统,在热电转换中具有独特的优势。本文主要研究光场、磁场、库仑相互作用以及量子相干性等重要因素对于两种典型的量子点热电热机的热力学性能的影响,其研究结果为调控和优化微观热电热机的热力学性能提供了有效方法,这对设计和制造微观热电热机具有实际意义。本文共有图29幅,参考文献113篇。更多还原

【Abstract】 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.更多还原