中国物理B ›› 2020, Vol. 29 ›› Issue (8): 86502-086502.doi: 10.1088/1674-1056/ab99af

所属专题: SPECIAL TOPIC — Phononics and phonon engineering

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Ultra-low thermal conductivity of roughened silicon nanowires: Role of phonon-surface bond order imperfection scattering

Heng-Yu Yang(杨恒玉), Ya-Li Chen(陈亚利), Wu-Xing Zhou(周五星), Guo-Feng Xie(谢国锋), Ning Xu(徐宁)   

  1. 1 School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;
    2 Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion, Xiangtan 411201, China;
    3 School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China;
    4 Deparment of Physics, Yancheng Institute of Technology, Yancheng 224051, China
  • 收稿日期:2020-03-31 修回日期:2020-06-04 出版日期:2020-08-05 发布日期:2020-08-05
  • 通讯作者: Guo-Feng Xie, Guo-Feng Xie E-mail:gfxie@xtu.edu.cn;nxu@ycit.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11874145).

Ultra-low thermal conductivity of roughened silicon nanowires: Role of phonon-surface bond order imperfection scattering

Heng-Yu Yang(杨恒玉)1,2, Ya-Li Chen(陈亚利)3, Wu-Xing Zhou(周五星)1,2, Guo-Feng Xie(谢国锋)1,2, Ning Xu(徐宁)4,2   

  1. 1 School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;
    2 Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion, Xiangtan 411201, China;
    3 School of Physics and Optoelectronics, Xiangtan University, Xiangtan 411105, China;
    4 Deparment of Physics, Yancheng Institute of Technology, Yancheng 224051, China
  • Received:2020-03-31 Revised:2020-06-04 Online:2020-08-05 Published:2020-08-05
  • Contact: Guo-Feng Xie, Guo-Feng Xie E-mail:gfxie@xtu.edu.cn;nxu@ycit.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11874145).

摘要:

The ultra-low thermal conductivity of roughened silicon nanowires (SiNWs) can not be explained by the classical phonon-surface scattering mechanism. Although there have been several efforts at developing theories of phonon-surface scattering to interpret it, but the underlying reason is still debatable. We consider that the bond order loss and correlative bond hardening on the surface of roughened SiNWs will deeply influence the thermal transport because of their ultra-high surface-to-volume ratio. By combining this mechanism with the phonon Boltzmann transport equation, we explicate that the suppression of high-frequency phonons results in the obvious reduction of thermal conductivity of roughened SiNWs. Moreover, we verify that the roughness amplitude has more remarkable influence on thermal conductivity of SiNWs than the roughness correlation length, and the surface-to-volume ratio is a nearly universal gauge for thermal conductivity of roughened SiNWs.

关键词: thermal conductivity, silicon nanowires, bond order imperfections, phonon-surface scattering

Abstract:

The ultra-low thermal conductivity of roughened silicon nanowires (SiNWs) can not be explained by the classical phonon-surface scattering mechanism. Although there have been several efforts at developing theories of phonon-surface scattering to interpret it, but the underlying reason is still debatable. We consider that the bond order loss and correlative bond hardening on the surface of roughened SiNWs will deeply influence the thermal transport because of their ultra-high surface-to-volume ratio. By combining this mechanism with the phonon Boltzmann transport equation, we explicate that the suppression of high-frequency phonons results in the obvious reduction of thermal conductivity of roughened SiNWs. Moreover, we verify that the roughness amplitude has more remarkable influence on thermal conductivity of SiNWs than the roughness correlation length, and the surface-to-volume ratio is a nearly universal gauge for thermal conductivity of roughened SiNWs.

Key words: thermal conductivity, silicon nanowires, bond order imperfections, phonon-surface scattering

中图分类号:  (Thermal properties of small particles, nanocrystals, nanotubes, and other related systems)

  • 65.80.-g
63.22.-m (Phonons or vibrational states in low-dimensional structures and nanoscale materials)