Phononic Thermal Transport along Graphene Grain Boundaries: A Hidden Vulnerability.
Adv Sci (Weinh)
; 8(18): e2101624, 2021 Sep.
Article
en En
| MEDLINE
| ID: mdl-34291609
ABSTRACT
While graphene grain boundaries (GBs) are well characterized experimentally, their influence on transport properties is less understood. As revealed here, phononic thermal transport is vulnerable to GBs even when they are ultra-narrow and aligned along the temperature gradient direction. Non-equilibrium molecular dynamics simulations uncover large reductions in the phononic thermal conductivity (κp ) along linear GBs comprising periodically repeating pentagon-heptagon dislocations. Green's function calculations and spectral energy density analysis indicate that the origin of the κp reduction is hidden in the periodic GB strain field, which behaves as a reflective diffraction grating with either diffuse or specular phonon reflections, and represents a source of anharmonic phonon-phonon scattering. The non-monotonic dependence with dislocation density of κp uncovered here is unaccounted for by the classical Klemens theory. It can help identify GB structures that can best preserve the integrity of the phononic transport.
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1
Colección:
01-internacional
Banco de datos:
MEDLINE
Idioma:
En
Revista:
Adv Sci (Weinh)
Año:
2021
Tipo del documento:
Article
País de afiliación:
China