Thermal Conductance Degradation and Phonon Scattering at Graphene-Silicon Interfacial Defect Boundaries

International Journal of Physics | Vol. 6, No. 6, June 2015 | pp. 41–48

DOI: 10.46882/2015/IJP/000062

Research Article

Title: Thermal Conductance Degradation and Phonon Scattering at Graphene-Silicon Interfacial Defect Boundaries

Names of Authors: D. W. Meyer¹, C. H. Jenkins²

Authors’ Affiliations: ¹Institute of Physics, Karlsruher Institut für Technologie, Karlsruhe, Germany; ²Space Sciences Laboratory, University of California, Berkeley, California, USA

Abstract: Dissipating heat efficiently across mismatched material boundaries is a major technical challenge in modern high-power nanoelectronics. This paper uses molecular dynamics simulations to quantify thermal conductance degradation and track phonon wavepacket scattering at defective graphene-silicon (Gr-Si) interfaces. We constructed atomistic models using the optimized Tersoff and Stillinger-Weber potentials, incorporating varying concentrations of interfacial point defects and vacancy networks. Longitudinal and transverse acoustic phonon wavepackets were generated with narrow frequency spreads centered between 3.0 THz and 10.0 THz. The computational data demonstrate that high-frequency acoustic phonons (f greater than 6.0 THz) undergo strong diffuse scattering at the defective interface, dropping the transmission coefficient from 0.74 down to 0.18. This diffuse scattering is driven by localized strain fields and localized interface vibrational modes. The overall interfacial thermal conductance was calculated to decrease by 52.0% when the interfacial defect density scaled from 1.0% to 5.0% at 300.0 K. These molecular dynamics calculations clarify the atomic-scale mechanisms restricting heat carrier propagation, helping engineers design targeted thermal management solutions for graphene-based devices.

Keywords: Thermal conductance; phonon scattering; molecular dynamics; graphene-silicon interface; defect density; nanoelectronics

Manuscript Timeline: Received: March 04, 2015; Revised: April 22, 2015; Accepted: May 10, 2015; Published: June 18, 2015

Citation: Meyer, D. W., & Jenkins, C. H. (2015). Thermal Conductance Degradation and Phonon Scattering at Graphene-Silicon Interfacial Defect Boundaries. International Journal of Physics, 6(6), 41–48.

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