Thermal Dispersion Metrics and Phonon Scattering at Silicon-Carbide Superlattice Interfaces

International Journal of Physics | Vol. 13, No. 6, June 2022 | pp. 41–48

DOI: 10.46882/2022/IJP/000146

Research Article

Title: Thermal Dispersion Metrics and Phonon Scattering at Silicon-Carbide Superlattice Interfaces

Names of Authors: M. G. Richter¹, D. W. Meyer²

Authors’ Affiliations:
¹ Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany
² Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany

Abstract: Effectively dissipating heavy thermal loads across mismatched semiconductor boundaries is a major technical hurdle in developing next-generation wide-bandgap high-power electronics and electric vehicle control modules. This paper uses molecular dynamics simulations to quantify thermal dispersion metrics and track phonon wavepacket scattering at defective silicon-carbide (Si-SiC) superlattice interfaces. We constructed atomistic models using the optimized Tersoff empirical potentials, incorporating varying concentrations of interfacial dislocation networks and chemical grading steps. Longitudinal and transverse acoustic phonon wavepackets were generated with narrow frequency spreads centered between 2.0 THz and 10.0 THz. The computational data demonstrate that high-frequency acoustic phonons (f greater than 5.5 THz) undergo strong diffuse scattering at the rough interface, dropping the calculated transmission coefficient from 0.82 down to 0.18. This transport degradation is driven by severe acoustic impedance mismatch and localized interface vibrational modes. The overall interfacial thermal conductance was calculated to decrease by 46.0% when the interface roughness parameter scaled from 0.1 nm to 0.6 nm at 300.0 K. These molecular dynamics calculations clarify the atomic-scale paths limiting heat carrier propagation, helping engineers design targeted thermal management interfaces.

Keywords: Thermal conductance; phonon wavepacket; molecular dynamics; superlattice interfaces; silicon carbide; electronics cooling

Manuscript Timeline: Received: March 02, 2022; Revised: April 14, 2022; Accepted: May 02, 2022; Published: June 15, 2022

Citation: Richter, M. G., & Meyer, D. W. (2022). Thermal Dispersion Metrics and Phonon Scattering at Silicon-Carbide Superlattice Interfaces. International Journal of Physics, 13(6), 41–48.

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