Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Interfacial Defect Boundaries

International Journal of Physics | Vol. 7, No. 9, September 2016 | pp. 65–72

DOI: 10.46882/2016/IJP/000077

Research Article

Title: Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Interfacial Defect Boundaries

Names of Authors: M. G. Richter¹, S. P. Nair²

Authors’ Affiliations: ¹Max-Planck-Institut für Festkörperforschung, Stuttgart, Germany; ²Department of Physics, University of Kerala, Trivandrum, India

Abstract: Minimizing thermal transport across semiconductor boundary layers is crucial for designing high-efficiency solid-state thermoelectric cooling devices. This paper uses molecular dynamics simulations to quantify thermal dispersion metrics and track phonon wavepacket scattering at defective silicon-silicide (Si-MSi2) interfaces. We constructed atomistic models using the optimized Stillinger-Weber potential, incorporating varying concentrations of interfacial point defects and atomic roughness steps. Longitudinal and transverse acoustic phonon wavepackets were generated with narrow frequency spreads centered between 2.0 THz and 8.0 THz. The computational data demonstrate that high-frequency acoustic phonons (f greater than 5.0 THz) undergo strong diffuse scattering at the rough interface, dropping the transmission coefficient from 0.85 down to 0.22. This diffuse scattering is driven by localized strain fields and localized interface vibrational modes. The overall interfacial thermal conductance was calculated to decrease by 48.0% when the interfacial roughness parameter scaled from 0.1 nm to 0.6 nm at 300.0 K. These molecular dynamics calculations clarify the atomic-scale mechanisms restricting heat carrier propagation, helping engineers design targeted thermal barriers for nanoscale electronics.

Keywords: Thermal dispersion; phonon wavepacket; molecular dynamics; interface roughness; thermoelectric cooling; silicide interfaces

Manuscript Timeline: Received: May 14, 2016; Revised: July 08, 2016; Accepted: August 03, 2016; Published: September 10, 2016

Citation: Richter, M. G., & Nair, S. P. (2016). Thermal Dispersion Metrics and Phonon Wavepacket Scattering at Silicon-Silicide Interfacial Defect Boundaries. International Journal of Physics, 7(9), 65–72.

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