低维材料电子/声子热输运特性的量子分析

项目名称： 低维材料电子/声子热输运特性的量子分析

项目编号： No.51276202

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 能源与动力工程

项目作者： 吕树申

作者单位： 中山大学

项目金额： 80万元

中文摘要： 低维材料由于其晶体结构的尺寸效应及量子效应而表现出优异的热学、电学及光学等物理性能，对其热物理性质准确预测的研究是其应用于热电转换、光电转换、探针等领域的关键课题之一，开展相关研究具有重要的科学意义和实用价值。本项目将采用基于量子力学的密度泛函理论结合非平衡格林函数的、能够有效描述低维材料电子/声子热输运性质的第一性原理计算方法，以金纳米线及薄膜、硅纳米线及薄膜、碳纳米管为典型的金属导体、半导体等低维材料，揭示其电子/声子分别对热输运特性的作用及非连续性介质中量子力学的作用机理，分析一维材料体系的非傅里叶导热问题，获得低维材料的热输运规律及热物性预测模型，计算结果与相关实验结果进行对比；根据半导体薄膜材料热/电物理性质的分析结果及其导热/导电特点，进一步设计高效热电材料及其优化结构，获得理论与实验相符的以二氧化钛纳米管阵列薄膜为主体的高性能热电材料，为实际应用提供科学依据。

中文关键词： 电子/声子热输运；低维材料；导热；非平衡格林函数方法；热电材料

英文摘要： Low-dimensional materials have demonstrated extraordinary thermal, electrical and optical properties due to the size and quantum effect of their crystal structures. It is a key issue to accurately predict the thermophysical properties of low-dimensional materials for their applications in the areas of thermoelectric conversion, photoelectric conversion and sensors. And it is of scientific significance and practical value to perform related investigations. The density functional theory (DFT) combined with nonequilibrium Green's function method (NEGF), both based on quantum mechanics, are used to study the thermal transport of electrons and phonons of low-dimensional materials totally from first principles. The transport mechanisms of electrons/phonons and anomalous non-Fourier conduction of one-dimensional systems are investigated by modeling the thermal transport of typical low-dimensional metallic conductors and semiconductors, such as gold nanowires/membranes, silicon nanowires/membranes and carbon nanotubes. The thermal transport properties and models for predicting the thermophysical properties of low-dimensional materials are finally to realize. The computational results are also compared with related experimental data. Besides, according to the theoretical analysis of the electronic and phononic transport,

英文关键词： Electron/phonon heat transport；low-dimensional materials；heat conduction；NEGF；thermo-electronic material