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arXiv · 2104.04361

Phononic thermal transport along graphene grain boundaries

Zhen Tong·Alessandro Pecchia·ChiYung Yam·Traian Dumitricǎ·Thomas Frauenheim
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Abstract

We reveal that phononic thermal transport in graphene is not immune to grain boundaries (GBs) aligned along the direction of the temperature gradient. Non-equilibrium molecular dynamics simulations uncover a large reduction in the phononic thermal conductivity ($\kappa_p$) along linear ultra-narrow GBs comprising periodically-repeating pentagon-heptagon dislocations. Green's function calculations and spectral energy density analysis indicate that $\kappa_p$ is the complex manifestation of the periodic strain field, which behaves as a reflective diffraction grating with both diffuse and specular phonon reflections, and represents a source of anharmonic phonon-phonon scattering. Our findings provide new insights into the integrity of the phononic thermal transport in GB graphene.

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Zhen Tong, Alessandro Pecchia, ChiYung Yam, Traian Dumitricǎ, Thomas Frauenheim. 2021-04-09. Phononic thermal transport along graphene grain boundaries. https://arxiv.org/abs/2104.04361

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