Spectral analysis of phonon transport across an SiC–SiC nanogap

Abstract

Interfacial thermal conductance spectrum is of importance for manipulating phonon transport in nanoscale heat transfer. However, for the phonons across a vacuum nanogap due to quasi-Casimir coupling between two separated solid walls, the interfacial thermal conductance spectrum is not fully analyzed. In this study, classical nonequilibrium molecular dynamics simulations were conducted using the LAMMPS package to investigate phonon heat transfer across an SiC–SiC nanogap with various atomic surface terminations. The spectral thermal conductance of identical cases of Si–Si and C–C is significantly greater than that of the nonidentical cases of C–Si and Si–C. In identical cases, the acoustic phonons are dominant in phonon heat transfer across the nanogap for Si–Si, whereas the optical phonons (18–22 THz) are the main heat carriers for C–C. Consequently, phonon transport across a vacuum nanogap can be enhanced by aligning the identical atoms at atomic surface terminated layers.

Wentao Chen

Research Fellow

My research interests include near-field heat transfer, thermal transport at the solid-solid and solid-liquid interface, and molecular dynamics simulation.