Lattice-dynamical calculation of phonon scattering at ideal Si-Ge interfaces

H. Zhao, J. B. Freund

Research output: Contribution to journalArticlepeer-review

Abstract

Detailed phonon scattering at an ideal Si-Ge interface is studied with a linear lattice dynamics model. Frequency dependent transmission coefficients indicate the significance of acoustic-optical phonon mode conversion at the interface. Applied to multiple interfaces, the method shows how the overall thermal resistance approaches a finite (Bloch mode) limit with the increasing number of interfaces in absence of other scattering mechanisms. The dependence of thermal resistance on the superlattice layer thickness is not significant even in the interface-scattering-only limit we study. We also assess errors incurred by the finite domain size and classical statistics in molecular dynamics simulations of interface thermal resistance. Results suggest that using 6×6 unit cells in the transverse directions, a tractable size for such simulations, will incur only a 5% error in the predicted thermal resistance. Similarly, the error due to the classical (Boltzmann) phonon distribution in molecular dynamics simulations is predicted to be less than 10% for temperatures above 300 K.

Original languageEnglish (US)
Article number024903
JournalJournal of Applied Physics
Volume97
Issue number2
DOIs
StatePublished - Jan 15 2005

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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