Edge effect on thermal transport in graphene nanoribbons: A phonon localization mechanism beyond edge roughness scattering

Yan Wang, Purdue University
Bo Qiu, Birck Nanotechnology Center, Purdue University
Xiulin Ruan, Birck Nanotechnology Center, Purdue University

Date of this Version



Yan Wang, Bo Qiu and Xiulin Ruan. Appl. Phys. Lett. 101, 013101 (2012); http://dx.doi.org/10.1063/1.4732155


Copyright (2012) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Appl. Phys. Lett. 101, 013101 (2012) and may be found at http://dx.doi.org/10.1063/1.4732155. The following article has been submitted to/accepted by Applied Physics Letters. Copyright (2012) Yan Wang, Bo Qiu and Xiulin Ruan. This article is distributed under a Creative Commons Attribution 3.0 Unported License.


Equilibrium molecular dynamics simulations show that graphene nanoribbons (GNRs) with zigzag edges have higher thermal conductivity (kappa) than armchair-edged ones, and the difference diminishes with increasing temperature or ribbon width. The dominant phonon wavelength for thermal transport can be much longer (by orders of magnitude) than the difference between the "roughness" of smooth zigzag and armchair edges. Therefore, the roughness scattering theory is not sufficient to explain the largely different kappa of GNRs with different edge chiralities. Cross-sectional decomposition of the steady-state heat flux shows significant suppression of thermal transport at edges, especially in armchair ones. This behavior is explored by phonon spectra analysis. Considerable phonon localization at edges is concluded to underlie the edge-chirality dependent kappa of GNRs. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4732155]


Nanoscience and Nanotechnology