In-Plane Thermal Conductivity of Polycrystalline Chemical Vapor Deposition Graphene with Controlled Grain Sizes

Woomin Lee, Kenneth David Kihm, Hong Goo Kim, Seungha Shin, Changhyuk Lee, Jae Sung Park, Sosan Cheon, Oh Myoung Kwon, Gyumin Lim, Woorim Lee

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28 Citations (Scopus)

Abstract

Manipulation of the chemical vapor deposition graphene synthesis conditions, such as operating P, T, heating/cooling time intervals, and precursor gas concentration ratios (CH4/H2), allowed for synthesis of polycrystalline single-layered graphene with controlled grain sizes. The graphene samples were then suspended on 8 μm diameter patterned holes on a silicon-nitride (Si3N4) substrate, and the in-plane thermal conductivities k(T) for 320 K < T < 510 K were measured to be 2660-1230, 1890-1020, and 680-340 W/m·K for average grain sizes of 4.1, 2.2, and 0.5 μm, respectively, using an opto-thermal Raman technique. Fitting of these data by a simple linear chain model of polycrystalline thermal transport determined k = 5500-1980 W/m·K for single-crystal graphene for the same temperature range above; thus, significant reduction of k was achieved when the grain size was decreased from infinite down to 0.5 μm. Furthermore, detailed elaborations were performed to assess the measurement reliability of k by addressing the hole-edge boundary condition, and the air-convection/radiation losses from the graphene surface.

Original languageEnglish
Pages (from-to)2361-2366
Number of pages6
JournalNano Letters
Volume17
Issue number4
DOIs
Publication statusPublished - 2017 Apr 12

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Keywords

  • CVD
  • grain size effect
  • Graphene
  • thermal conductivity

ASJC Scopus subject areas

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

Cite this

Lee, W., Kihm, K. D., Kim, H. G., Shin, S., Lee, C., Park, J. S., Cheon, S., Kwon, O. M., Lim, G., & Lee, W. (2017). In-Plane Thermal Conductivity of Polycrystalline Chemical Vapor Deposition Graphene with Controlled Grain Sizes. Nano Letters, 17(4), 2361-2366. https://doi.org/10.1021/acs.nanolett.6b05269