Modulation of thermal conductivity in kinked silicon nanowires: Phonon interchanging and pinching effects

Jin Wu Jiang, Nuo Yang, Bing Shen Wang, Timon Rabczuk

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

We perform molecular dynamics simulations to investigate the reduction of the thermal conductivity by kinks in silicon nanowires. The reduction percentage can be as high as 70% at room temperature. The temperature dependence of the reduction is also calculated. By calculating phonon polarization vectors, two mechanisms are found to be responsible for the reduced thermal conductivity: (1) the interchanging effect between the longitudinal and transverse phonon modes and (2) the pinching effect, that is, a new type of localization, for the twisting and transverse phonon modes in the kinked silicon nanowires. Our work demonstrates that the phonon interchanging and pinching effects, induced by kinking, are brand-new and effective ways in modulating heat transfer in nanowires, which enables the kinked silicon nanowires to be a promising candidate for thermoelectric materials.

Original languageEnglish
Pages (from-to)1670-1674
Number of pages5
JournalNano Letters
Volume13
Issue number4
DOIs
Publication statusPublished - 2013 Apr 10
Externally publishedYes

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Keywords

  • Kinked silicon nanowire
  • phonon localization
  • phonon pinching effect
  • thermal conductivity

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanical Engineering

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