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人工晶体学报 ›› 2023, Vol. 52 ›› Issue (2): 289-297.

• 研究论文 • 上一篇    下一篇

基于第一性原理的单层WS2热输运特性研究

关斌, 刘远超, 张厚梁, 钟建斌, 邵钶, 蒋旭浩, 徐一帆   

  1. 北京石油化工学院机械工程学院,北京 102617
  • 收稿日期:2022-11-07 出版日期:2023-02-15 发布日期:2023-03-08
  • 通信作者: 刘远超,博士,副教授。E-mail:liuyuanchao@bipt.edu.cn
  • 作者简介:关斌(1998—),男,山西省人,硕士研究生。E-mail:gban1182259381@163.com
  • 基金资助:
    国家自然科学基金(51106012)

First-Principles Investigation on Thermal Transport Properties of Monolayer WS2

GUAN Bin, LIU Yuanchao, ZHANG Houliang, ZHONG Jianbin, SHAO Ke, JIANG Xuhao, XU Yifan   

  1. School of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, China
  • Received:2022-11-07 Online:2023-02-15 Published:2023-03-08

摘要: 二维WS2是一种层状过渡金属硫化物,因其具有特殊的层状结构、可调带隙及稳定的物理化学性质而备受关注。结合玻尔兹曼输运方程(BTE)和密度泛函理论(DFT),利用第一性原理研究了单层WS2声子的输运特性,分析了声子的谐性效应和非谐性效应对WS2晶格热导率的影响机理,计算了其声子的临界平均自由程,提出通过调整阻断频率的方法来调控WS2的晶格热导率。研究结果表明:单层WS2在300 K时的本征晶格热导率为149.12 W/(m·K),且随温度的升高而降低;从各声子支对总热导率的贡献来看,声学声子支起主要作用,特别是纵向声学(longitudinal acoustic, LA)声子支对单层WS2热导率的贡献百分比最大(44.28%);单层WS2声学声子支和光学声子支之间的较大带隙(声光学声子支之间无散射)导致其具有较高的晶格热导率。本文研究可为基于单层WS2纳米电子器件的设计和改进提供借鉴和理论指导。

关键词: WS2, 层状过渡金属硫化物, 声子, 热输运特性, 第一性原理, 谐性效应, 晶格热导率

Abstract: As one kind of layered transition metal sulfides, Two-dimensional WS2 has attracted much attention because of its special layered structure, tunable band gap and stable physicochemical properties. Combining Boltzmann transport equation (BTE) and density functional theory (DFT), the phonon transport properties of monolayer WS2 were investigated by first-principles. The harmonic and anharmonic effects of phonons to the lattice thermal conductivity of WS2 were analyzed. The critical mean free path of phonon for WS2 was calculated, which demonstrated that the thermal conductivity of WS2 could be regulated by adjusting the frequency. The results show that the intrinsic lattice thermal conductivity of monolayer WS2 is 149.12 W/(m·K) at 300 K, and it will decrease with the increase of temperature. The acoustic phonon branches play a major role among all phonon branches to the total thermal conductivity of monolayer WS2, especially the longitudinal acoustic (LA) branch whose contribution percentage is 44.28%. There is a big band gap (no scattering) between the acoustic and optical branches, which is found to be responsible for the higher lattice thermal conductivity of monolayer WS2. This investigation could provide a reference and theoretical guidance for the design and improvement of monolayer WS2 based nano-electronic devices.

Key words: WS2, layered transition metal sulfide, phonon, thermal transport property, first-principle, harmonic effect, lattice thermal conductivity

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