Effect of surface roughness on thermal conductivity of VLS-grown rough Si1-x Ge x nanowires

Hyoungjoon Kim, Yong Hee Park, Ilsoo Kim, Jungwon Kim, Heon-Jin Choi, Woochul Kim

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

The recent demonstration of thermal conductivity of rough electrolessly etched Si nanowire (Hochbaum et al., Nature, 451:163, 2008) attracted a lot of interest, because it could not be explained by the existing theory; thermal conductivity of rough Si nanowires falls below the boundary scattering of the thermal conductivity. However, nanoscale pores presented in the nanowires (Hochbaum et al., Nano Letters, 9:3550-3554, 2009) hinder one to be fully convinced that the surface roughness solely made a contribution to the significant reduction in thermal conductivity. In this study, we synthesized vapor-liquid-solid (VLS) grown rough Si1-xGex nanowire and measured and theoretically simulated thermal conductivity of the nanowire. The thermal conductivity of rough Si0.96Ge0.04 nanowire is an order of magnitude lower than that of bulk Si0.96Ge0.04 and around a factor of four times lower than that of smooth Si 0.96Ge0.04 nanowire. This significant reduction could be explained by the fact that the surface roughness scatters medium-wavelength phonons, whereas the long-wavelength phonons are scattered by phonon boundary scattering, and the short-wavelength phonons are scattered by alloy scattering.

Original languageEnglish
Pages (from-to)23-28
Number of pages6
JournalApplied Physics A: Materials Science and Processing
Volume104
Issue number1
DOIs
Publication statusPublished - 2011 Jul 1

Fingerprint

Nanowires
Thermal conductivity
Surface roughness
Vapors
Liquids
Phonons
Scattering
Wavelength
Demonstrations

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)

Cite this

@article{89cdb8b96178493e941f8f91e22703f5,
title = "Effect of surface roughness on thermal conductivity of VLS-grown rough Si1-x Ge x nanowires",
abstract = "The recent demonstration of thermal conductivity of rough electrolessly etched Si nanowire (Hochbaum et al., Nature, 451:163, 2008) attracted a lot of interest, because it could not be explained by the existing theory; thermal conductivity of rough Si nanowires falls below the boundary scattering of the thermal conductivity. However, nanoscale pores presented in the nanowires (Hochbaum et al., Nano Letters, 9:3550-3554, 2009) hinder one to be fully convinced that the surface roughness solely made a contribution to the significant reduction in thermal conductivity. In this study, we synthesized vapor-liquid-solid (VLS) grown rough Si1-xGex nanowire and measured and theoretically simulated thermal conductivity of the nanowire. The thermal conductivity of rough Si0.96Ge0.04 nanowire is an order of magnitude lower than that of bulk Si0.96Ge0.04 and around a factor of four times lower than that of smooth Si 0.96Ge0.04 nanowire. This significant reduction could be explained by the fact that the surface roughness scatters medium-wavelength phonons, whereas the long-wavelength phonons are scattered by phonon boundary scattering, and the short-wavelength phonons are scattered by alloy scattering.",
author = "Hyoungjoon Kim and Park, {Yong Hee} and Ilsoo Kim and Jungwon Kim and Heon-Jin Choi and Woochul Kim",
year = "2011",
month = "7",
day = "1",
doi = "10.1007/s00339-011-6475-0",
language = "English",
volume = "104",
pages = "23--28",
journal = "Applied Physics",
issn = "0340-3793",
publisher = "Springer Heidelberg",
number = "1",

}

Effect of surface roughness on thermal conductivity of VLS-grown rough Si1-x Ge x nanowires. / Kim, Hyoungjoon; Park, Yong Hee; Kim, Ilsoo; Kim, Jungwon; Choi, Heon-Jin; Kim, Woochul.

In: Applied Physics A: Materials Science and Processing, Vol. 104, No. 1, 01.07.2011, p. 23-28.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of surface roughness on thermal conductivity of VLS-grown rough Si1-x Ge x nanowires

AU - Kim, Hyoungjoon

AU - Park, Yong Hee

AU - Kim, Ilsoo

AU - Kim, Jungwon

AU - Choi, Heon-Jin

AU - Kim, Woochul

PY - 2011/7/1

Y1 - 2011/7/1

N2 - The recent demonstration of thermal conductivity of rough electrolessly etched Si nanowire (Hochbaum et al., Nature, 451:163, 2008) attracted a lot of interest, because it could not be explained by the existing theory; thermal conductivity of rough Si nanowires falls below the boundary scattering of the thermal conductivity. However, nanoscale pores presented in the nanowires (Hochbaum et al., Nano Letters, 9:3550-3554, 2009) hinder one to be fully convinced that the surface roughness solely made a contribution to the significant reduction in thermal conductivity. In this study, we synthesized vapor-liquid-solid (VLS) grown rough Si1-xGex nanowire and measured and theoretically simulated thermal conductivity of the nanowire. The thermal conductivity of rough Si0.96Ge0.04 nanowire is an order of magnitude lower than that of bulk Si0.96Ge0.04 and around a factor of four times lower than that of smooth Si 0.96Ge0.04 nanowire. This significant reduction could be explained by the fact that the surface roughness scatters medium-wavelength phonons, whereas the long-wavelength phonons are scattered by phonon boundary scattering, and the short-wavelength phonons are scattered by alloy scattering.

AB - The recent demonstration of thermal conductivity of rough electrolessly etched Si nanowire (Hochbaum et al., Nature, 451:163, 2008) attracted a lot of interest, because it could not be explained by the existing theory; thermal conductivity of rough Si nanowires falls below the boundary scattering of the thermal conductivity. However, nanoscale pores presented in the nanowires (Hochbaum et al., Nano Letters, 9:3550-3554, 2009) hinder one to be fully convinced that the surface roughness solely made a contribution to the significant reduction in thermal conductivity. In this study, we synthesized vapor-liquid-solid (VLS) grown rough Si1-xGex nanowire and measured and theoretically simulated thermal conductivity of the nanowire. The thermal conductivity of rough Si0.96Ge0.04 nanowire is an order of magnitude lower than that of bulk Si0.96Ge0.04 and around a factor of four times lower than that of smooth Si 0.96Ge0.04 nanowire. This significant reduction could be explained by the fact that the surface roughness scatters medium-wavelength phonons, whereas the long-wavelength phonons are scattered by phonon boundary scattering, and the short-wavelength phonons are scattered by alloy scattering.

UR - http://www.scopus.com/inward/record.url?scp=79959231789&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79959231789&partnerID=8YFLogxK

U2 - 10.1007/s00339-011-6475-0

DO - 10.1007/s00339-011-6475-0

M3 - Article

VL - 104

SP - 23

EP - 28

JO - Applied Physics

JF - Applied Physics

SN - 0340-3793

IS - 1

ER -