Thermal conductivity of graphene grain boundaries along arbitrary in-plane directions: A comprehensive molecular dynamics study

Abstract

The thermal conductivity of polycrystalline graphene is expected to be lower than that of pristine graphene, due to the existence of defects, such as grain boundaries (GBs). To study the thermal transport behavior in polycrystalline graphene, it is crucial to understand the thermal conductivity of graphene GBs as a function of the tilt GB misorientation angle and in-plane thermal loading angle. However, existing studies of thermal conductivity of graphene GBs only consider the case where the thermal flux is perpendicular or parallel to the graphene GB. To address this issue, here we perform systematic non-equilibrium molecular dynamics simulations and investigate the thermal conductivity of graphene GBs for all possible tilt GB misorientation angles (23 cases) under arbitrary in-plane thermal loading directions. The findings from the present study can offer quantitative guidance for using polycrystalline graphene in thermal devices and flexible electronics applications.

Observation of the transition state of domain wall displacement and GMI effect of FINEMET/graphene composite ribbons

“…The reason for the emergence of the C peak was hydrogen annealing caused new chemical bonds between graphene layer and the FINEMET ribbon, such as Si-H and Si-H 2 bond. 14 There were three main effects for the FINEMET/ graphene composite ribbons during the hydrogen annealing process: [15][16][17][18][19] the rst was to remove contaminants (PMMA, etc. ), the second was to saturate the surface metal dangling bonds, and the third was to form hydrogen bonds and Si-H bonds to increase adhesion between the FINEMET ribbon and graphene.…”

Defect-Engineered Thermal Transport in Wrinkled Graphene: A Comprehensive Molecular Dynamics Study

“…28 Besides, Fox et al investigated the effects of thermal loading direction and the grain boundary misorientation angle on the thermal conductivity of graphene with grain boundaries. 29 They found that the thermal conductivity generally decreases with increasing defect density along the grain boundaries, but increases with increasing the loading angle. Analogously, the formation of wrinkles could also decrease the thermal conductivity.…”

Phononic Thermal Transport along Graphene Grain Boundaries: A Hidden Vulnerability

“…[ 13 ] In graphene, GBs are strings of pentagon‐heptagon (5‐7) edge dislocations [ 10 , 14 , 15 , 16 ] and their organization can gives rise to diverse GB shapes. While in general the thermal gradient can have an arbitrary orientation with respect to the GB line, [ 17 , 18 ] only transport across GBs is perceived to have a significantly impact on heat transport. Green's function (GF) calculations [ 19 , 20 ] obtained that heat transmission across GBs can be influenced by the GB structure, size, and shape.…”