Characterizing thermal conduction in polycrystalline graphene

Abstract

Thermal conduction was explored and discussed through a combined theoretical and simulation approach in this work. The thermal conductivity k of polycrystalline graphene was calculated by molecular dynamics simulations based on a hexagonal patch model in close consistence with microstructural characterization in experiments. The effects of grain size, alignment, and temperature were identified with discussion on the microscopic phonon scattering mechanisms. The effective thermal conductivity is found to increase with the grain size and decrease with the mismatch angle and dislocation density at the grain boundaries. The 1/T temperature dependence of k is significantly weakened in the polycrystals. The effect of grain boundaries in modifying thermal transport properties of graphene was characterized by their effective width and thermal conductivity as an individual phase, which was later included in a predictive effective medium model that showed degraded reduction in thermal conductivity for grain larger than a few microns.

References in corpus (5)

• Thermal properties of graphene: Fundamentals and applications
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• Anomalous Size Dependence of the Thermal Conductivity of Graphene Ribbons
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Cited by in corpus (5)

• Force and heat current formulas for many-body potentials in molecular dynamics simulation with applications to thermal conductivity calculations
• Hydrogenation of Penta-Graphene Leads to Unexpected Large Improvement in Thermal Conductivity
• Scaling Properties of Polycrystalline Graphene: A Review
• Electrical and thermal transport in coplanar polycrystalline graphene-hBN heterostructures
• Bimodal grain-size scaling of thermal transport in polycrystalline graphene from large-scale molecular dynamics simulations