Effects of pre-stress and surface stress on phonon thermal conductivity of rectangular Si nanowires

Linli Zhu, Haihui Ruan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

5 Citations (Scopus)

Abstract

This work investigates theoretically the phonon property and thermal conductivity of rectangular silicon nanowires under pre-stress and surface stress. In the framework of elasticity theory, the effects of spatial confinement are considered in the phonon dispersion relation of a stressed nanowire. The surface energy, which brings about the variation of the elastic modulus of nanowire and the influence on the phonon property, is then involved. Under a pre-stress field, the acoustoelastic effect gives rise to the change of phonon properties and thermal conductivity. Our numerical results demonstrate that the applied surface stress and pre-stress field can alter the phonon dispersion relation of a silicon nanowire significantly. The phonon energy increases if the surface stress is negative and the pre-stress is positive, and vice versa. The changes of phonon dispersion relation as well as the various phonon scattering rates lead to the variation of phonon thermal conductivity, which is the consequence of the surface stress and pre-stress fields. We further elaborate the size and temperature dependence of phonon thermal conductivity under different applied surface stresses and pre-stress fields and suggest using the strain engineering to tune the thermal performance of semiconductor nanostructures.
Original languageEnglish
Pages (from-to)253-263
Number of pages11
JournalApplied Physics A: Materials Science and Processing
Volume119
Issue number1
DOIs
Publication statusPublished - 1 Jan 2015

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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