Dependence of the In-Plane Thermal Conductivity of Graphene on

Article Cite This: Chem. Mater. XXXX, XXX, XXX−XXX

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Dependence of the In-Plane Thermal Conductivity of Graphene on Grain Misorientation Dongmok Lee,† Sanghoon Lee,‡ Byeong-Seon An,§ Tae-Hoon Kim,§ Cheol-Woong Yang,§ Ji Won Suk,*,⊥ and Seunghyun Baik*,⊥,∥ †

Institute of Advanced Machinery and Technology, Sungkyunkwan University, Suwon 16419, Republic of Korea Department of Energy Science, Sungkyunkwan University, Suwon 16419, Republic of Korea § School of Advanced Material Science and Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea ⊥ School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea ∥ Center for Integrated Nanostructure Physics, Institute for Basic Science (IBS), Suwon 16419, Republic of Korea ‡

S Supporting Information *

ABSTRACT: The thermal transport across the grain boundary (GB) is inevitably encountered for large-area polycrystalline graphene. However, the influence of GB configuration on thermal transport is not well understood. Here we investigated the effect of grain misorientation angle on the in-plane thermal conductivity (κ) of suspended graphene by using the optothermal Raman technique. Graphene with well-defined grain orientation was synthesized on an electropolished, annealed, and oxygen plasma-treated single-crystalline Cu(111) substrate by low-pressure chemical vapor deposition. The κ was primarily dependent on the grain size of single-, bi-, and polycrystalline graphene, consistent with the Boltzmann transport model. Surprisingly, κ of bicrystalline graphene dramatically decreased with a slight misorientation (