Heat Dissipation Mechanism at Carbon Nanotube Junctions on Silicon Oxide Substrate

Abstract

This study investigates heat dissipation at carbon nanotube (CNT) junctions supported on silicon dioxide substrate using molecular dynamics simulations. The temperature rise in a CNT (∼top CNT) not making direct contact with the oxide substrate but only supported by other CNTs (∼bottom CNT) is observed to be hundreds of degree higher compared with the CNTs wellcontacted with the substrate at similar power densities. The analysis of spectral temperature decay of CNToxide system shows very fast intratube energy transfer in a CNT from highfrequency band to intermediatefrequency bands. The low frequency phonon band (0–5 THz) of top CNT shows twostage energy relaxation which results from the efficient coupling of low frequency phonons in the CNToxide system and the blocking of direct transport of highand intermediatefrequency phonons of top CNT to the oxide substrate by bottom CNT.