Thermal conductivity of VLS-grown rough Si nanowires with various surface roughnesses and diameters

Yong Hee Park, Jungwon Kim, Hyoungjoon Kim, Ilsoo Kim, Ki Young Lee, Dongjea Seo, Heon Jin Choi, Woochul Kim

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

In this paper, we synthesize VLS-grown rough Si nanowires using Mn as a catalyst with various surface roughnesses and diameters and measured their thermal conductivities. We grew the nanowires by a combination vapor-liquid-solid and vapor-solid mechanism for longitudinal and radial growth, respectively. The surface roughness was controlled from smooth up to about 37 nm by the radial growth. Our measurements showed that the thermal conductivity of rough surface Si nanowires is significantly lower than that of smooth surface nanowires and decreased with increasing surface roughness even though the diameter of the smooth nanowire was lower than that of the rough nanowires. Considering both nanowires were grown via the same growth mechanism, these outcomes clearly demonstrate that the rough surface induces phonon scattering and reduces thermal conductivity with this nanoscale-hole-free nanowires. Control of roughness induced phonon scattering in Si nanowires holds promise for novel thermoelectric devices with high figures of merit.

Original languageEnglish
Pages (from-to)7-14
Number of pages8
JournalApplied Physics A: Materials Science and Processing
Volume104
Issue number1
DOIs
Publication statusPublished - 2011 Jul

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)

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