Molecular Dynamics Studies on Ballistic Thermal Resistance of Graphene Nano-Junctions

• Published in: Communications in theoretical physics 2015-05, Vol.63 (5), p.619-624
• Main Author: 姚文俊 曹炳阳
• Format: Article
• Language: English
• Subjects: Constrictions; Dynamics; Graphene; Heat transfer; Molecular dynamics; Nanostructure; Simulation; Thermal resistance; 仿真系统; 分子动力学模拟; 动力学理论; 弹道; 热电阻; 石墨; 纳米带; 长度收缩
• ISSN: 0253-6102; 1572-9494
• DOI: 10.1088/0253-6102/63/5/619

Ballistic thermal resistance of graphene nano-junctions is investigated using non-equifibrium molecular dynamics simulation. The simulation system is consisted of two symmetrical trapezoidal or rectangular graphene nano- ribbons （GNRs） and a connecting nanoscale constriction in between. Prom the simulated temperature profile, a big temperature jump resulted from the constriction is found, which is proportionM to the heat current and corresponds to a local ballistic thermal resistance. Fixing the constriction width and the length of GNRs, this ballistic thermal resistance is independent of the width of the GNRs bottom layer, i.e., the convex angle. But interestingly, this thermal resistance has obvious size effect. It is inversely proportional to the constriction width and will disappear with the constriction being wider. Moreover, based on the phonon dynamics theory, a theoretical model of the ballistic thermal resistance in two-dimensional nano-systems is developed, which gives a good explanation on microcosmic level and agrees well with the simulation result quantitatively and qualitatively.