Yang Xiaoheng, Han Dan, Fan Hongzhao, Wang Man, Du Mu, Wang Xinyu
Institute of Thermal Science and Technology, Shandong University, Jinan 250061, China.
Phys Chem Chem Phys. 2021 Jan 6;23(1):123-130. doi: 10.1039/d0cp03191g.
Recently, a two-dimensional (2D) oxocarbon monolayer, graphether, has been arousing extensive attention owing to its excellent electrical properties. In this work, we calculate the lattice thermal conductivity (k) of graphether and graphene using first-principles calculations and the phonon Boltzmann transport equation. At 300 K, the lattice thermal conductivities of graphether and graphene along the armchair direction are 600.91 W m-1 K-1 and 3544.41 W m-1 K-1, respectively. Moreover, the electron localization function is employed to reveal the origin of the anisotropic k of graphether. Furthermore, the harmonic and anharmonic properties of graphether and graphene are analyzed. We attribute the lower k of graphether to the smaller phonon group velocity and shorter phonon lifetime. Finally, the size effects of phonon transport in graphether and graphene are studied, and the results show that the lattice thermal conductivities are significantly dependent on the system length. The analysis of phonon behaviors in our study contributes to an in-depth understanding of the thermal transport in graphether for the first time, which provides valuable guidelines for graphether-based phonon engineering applications and 2D nanoelectronic devices.
最近，一种二维（2D）含氧碳单层材料——石墨醚，因其优异的电学性能而引起了广泛关注。在这项工作中，我们使用第一性原理计算和声子玻尔兹曼输运方程计算了石墨醚和石墨烯的晶格热导率（k）。在300 K时，石墨醚和石墨烯沿扶手椅方向的晶格热导率分别为600.91 W m-1 K-1和3544.41 W m-1 K-1。此外，利用电子定位函数揭示了石墨醚各向异性k的起源。此外，还分析了石墨醚和石墨烯的谐性和非谐性性质。我们将石墨醚较低的k归因于较小的声子群速度和较短的声子寿命。最后，研究了石墨醚和石墨烯中声子输运的尺寸效应，结果表明晶格热导率显著依赖于系统长度。我们对声子行为的分析首次有助于深入理解石墨醚中的热输运，这为基于石墨醚的声子工程应用和二维纳米电子器件提供了有价值的指导。
