Tailoring the Thermal and Mechanical Properties of Graphene Film by Structural Engineering

Nan Wang; Majid Kabiri Samani; Hu Li; Lan Dong; Zhongwei Zhang; Peng Su; Shujing Chen; Jie Chen; Shirong Huang; Guangjie Yuan; Xiangfan Xu; Baowen Li; Klaus Leifer; Lilei Ye; Johan Liu

doi:10.1002/smll.201801346

Tailoring the Thermal and Mechanical Properties of Graphene Film by Structural Engineering

Small. 2018 Jun 21:e1801346. doi: 10.1002/smll.201801346. Online ahead of print.

Authors

Nan Wang¹, Majid Kabiri Samani¹, Hu Li², Lan Dong³, Zhongwei Zhang³, Peng Su¹, Shujing Chen⁴, Jie Chen³, Shirong Huang⁴, Guangjie Yuan⁴, Xiangfan Xu³, Baowen Li⁵, Klaus Leifer², Lilei Ye⁶, Johan Liu^{1

4}

Affiliations

¹ Electronics Materials and Systems Laboratory (EMSL), Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, Kemivägen 9, SE-412 96, Göteborg, Sweden.
² Division of Applied Materials Sciences, Department of Engineering Sciences, Angstrom Laboratory, Uppsala University, SE-752 37, Uppsala, Sweden.
³ Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, and Institute for Advanced Study, Tongji University, Shanghai, 200092, China.
⁴ SMIT Center, School of Automation and Mechanical Engineering, Shanghai University, 20 Changzhong Rd., Shanghai, 201800, China.
⁵ Department of Mechanical Engineering, University of Colorado, Boulder, CO, 80309, USA.
⁶ SHT Smart High Tech AB, Hugo Grauers gata 3B, SE-411 33, Göteborg, Sweden.

PMID: 29926528
DOI: 10.1002/smll.201801346

Abstract

Due to substantial phonon scattering induced by various structural defects, the in-plane thermal conductivity (K) of graphene films (GFs) is still inferior to the commercial pyrolytic graphite sheet (PGS). Here, the problem is solved by engineering the structures of GFs in the aspects of grain size, film alignment, and thickness, and interlayer binding energy. The maximum K of GFs reaches to 3200 W m^-1 K^-1 and outperforms PGS by 60%. The superior K of GFs is strongly related to its large and intact grains, which are over four times larger than the best PGS. The large smooth features about 11 µm and good layer alignment of GFs also benefit on reducing phonon scattering induced by wrinkles/defects. In addition, the presence of substantial turbostratic-stacking graphene is found up to 37% in thin GFs. The lacking of order in turbostratic-stacking graphene leads to very weak interlayer binding energy, which can significantly decrease the phonon interfacial scattering. The GFs also demonstrate excellent flexibility and high tensile strength, which is about three times higher than PGS. Therefore, GFs with optimized structures and properties show great potentials in thermal management of form-factor-driven electronics and other high-power-driven systems.

Keywords: grain size; graphene films; phonon transfer; thermal conductivity; turbostratic-stacking.