石墨烯纳米结构中的热控制以及热电性质的研究

Thermal transport and thermoelectric properties of carbon nano-materials have become a hot topic in condensed matter physics and material sciences, due to its potential application in thermal management and thermoelectric energy conversion. This project is thus devoted to studying thermal transport and thermoelectric properties in graphene nano-structures based on the nonequilibrium Green's function and molecular dynamics methods. In this project, (1) we will first study thermoelectric properties in graphene quantum confined structures such as quantum dots (QDs) and QD arrays, and investigate the dependence of transport properties on the structure and also the dependence of thermoelectric figure of merit (ZT) on the chemical potential. (2) Next, we will consider the thermoelectric properties in one-dimensional graphene anti-dot lattices, exploring the change of the phonon spectrum and heat conductance with the anti-dot size and pattern. We will also study the optimization of ZT. (3) Finally, we will investigate the thermoelectric properties and thermal transport in few-layer graphene. Through these studies, we expect to find the effective ways to control heat transport and to improve the thermoelectric figure of merit in graphene nano-materials, and thus to shed light on the application of graphene in heat management of micro- and nano-scale electronics and in thermoelectric energy conversion.

由于碳纳米材料在纳微尺度上的热管理（thermal management）和热电能量转换方面具有广泛的应用前景，其热输运与热电性质的研究逐渐成为当前凝聚态物理和材料科学的热点。本项目拟采用非平衡Green函数与分子动力学方法研究石墨烯纳米结构中的热输运和热电性质。主要内容为：（1）研究石墨烯量子点、量子点阵列限制结构中的热输运性质和热电性质，探讨限制结构的尺寸、形状对输运性质的影响，探究热电ZT值随结构及化学势的变化关系；（2）研究准一维的石墨烯网孔结构中孔的尺寸、排列方式对声子谱的改变以及引起的热导与电输运性质的变化，研究这类结构中ZT值的优化问题；（3）研究多层石墨烯材料中的热输运性质以及ZT值的优化方式。本项目的研究，旨在获得调控石墨烯纳米材料热导率的方式和提高其热电ZT值的途径，为石墨烯纳米材料在纳微电子学中的热管理与热电能量转化方面的应用提供理论依据。

由于低维材料在纳微尺度上的热管理（thermal management）和热电能量转换方面具有重要的应用前景，本项目采用非平衡Green函数与级联方程等方法研究石墨烯等纳米结构中的热输运和热电性质。（1）探讨了石墨烯量子点阵列、硅烯中的热输运性质和热电性质，研究了热电ZT值随结构、垂直电场及化学势的变化关系。（2）研究了量子点结构中最大输出功率的优化问题，以及电声相互作用对热输运性质的影响。（3）探讨了自旋维度对低维结构热电性质的影响。本项目的研究，初步阐明了调控石墨烯等纳米材料热导率的方式和提高其热电ZT值的途径，为低维材料在纳微电子学中的热管理与热电能量转化方面的应用提供理论依据。