Wu Xin, Han Qiang
Department of Engineering Mechanics, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, Guangdong Province 510640, People's Republic of China.
Nanotechnology. 2020 May 22;31(21):215708. doi: 10.1088/1361-6528/ab73bc. Epub 2020 Feb 7.
The exceptional thermal transport properties of graphene are affected due to the presence of various topological defects, which include single vacancy, double vacancies and Stone-Wales defects. The present article is intended to study on thermal transport properties of defective graphene by comparing the effects of topological defects on the thermal conductivity of graphene. This study developed a program for constructing defective graphene models with customizable defect concentrations and distribution types. The efficient molecular dynamics method based on graphics processing units is applied, which can achieve efficient and accurate calculation of material thermal conductivity. It is revealed that the existence of topological defects has a considerable reduce on the thermal conductivity of graphene, and the declining rate of the value get less with increasing defects concentration. At the same concentration, the weakening effect of SW defects on the thermal conductivity of graphene is evidently less than the other two defects. We also explored the effect of temperature on the thermal conductivity of graphene with different defects. These findings were discussed from the phonon perspective that elucidate the atomic level mechanisms, which provide guidance for thermal management of graphene devices.
由于存在各种拓扑缺陷，包括单空位、双空位和斯通-威尔士缺陷，石墨烯卓越的热输运特性受到影响。本文旨在通过比较拓扑缺陷对石墨烯热导率的影响，研究缺陷石墨烯的热输运特性。本研究开发了一个程序，用于构建具有可定制缺陷浓度和分布类型的缺陷石墨烯模型。应用了基于图形处理单元的高效分子动力学方法，该方法可以实现对材料热导率的高效且准确的计算。结果表明，拓扑缺陷的存在会使石墨烯的热导率大幅降低，且该值的下降速率随着缺陷浓度的增加而减小。在相同浓度下，斯通-威尔士缺陷对石墨烯热导率的削弱作用明显小于其他两种缺陷。我们还探讨了温度对具有不同缺陷的石墨烯热导率的影响。从声子角度对这些发现进行了讨论，阐明了原子水平的机制，为石墨烯器件的热管理提供了指导。
