Frequency and Polarization Dependence of Thermal Coupling between Carbon Nanotubes and SiO2

Abstract

We study heat dissipation from a (10,10) CNT to a SiO2 substrate using equilibrium and non-equilibrium classical molecular dynamics. The CNT-substrate thermal boundary conductance (TBC) is computed both from the relaxation time of the CNT-substrate temperature difference, and from the time autocorrelation function of the interfacial heat flux at equilibrium (Green-Kubo relation). The power spectrum of interfacial heat flux fluctuation and the time evolution of the internal CNT energy distribution suggest that: 1) thermal coupling is dominated by long wavelength phonons between 0-10 THz, 2) high frequency (40-57 THz) CNT phonon modes are strongly coupled to sub-40 THz CNT phonon modes, and 3) inelastic scattering between the CNT phonons and substrate phonons contributes to interfacial thermal transport. We also find that the low frequency longitudinal acoustic (LA) and twisting acoustic (TA) modes do not transfer energy to the substrate as efficiently as the low frequency transverse optical (TO) mode.

References in corpus (6)

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• Kapitza resistance at the liquid solid interface
• Molecular Dynamics Simulation of Thermal Boundary Conductance Between Carbon Nanotubes and SiO2
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Cited by in corpus (4)

• Thermal properties of graphene: Fundamentals and applications
• Frequency-dependent phonon mean free path in carbon nanotubes from non-equilibrium molecular dynamics
• Effect of substrate modes on thermal transport in supported graphene
• Reduction of Phonon Lifetimes and Thermal Conductivity of a Carbon Nanotube on Amorphous Silica