An ab initio study of multiple phonon scattering resonances in silicon germanium alloys
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mendoza_vca_JAP_revise.pdf
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Author(s)
Esfarjani, Keivan
Chen, Gang
Mendoza, Jonathan M.
Date Issued
May 2015
Journal
Journal of Applied Physics
Publisher
American Institute of Physics (AIP)
Citation
Mendoza, Jonathan, Keivan Esfarjani, and Gang Chen. “An Ab Initio Study of Multiple Phonon Scattering Resonances in Silicon Germanium Alloys.” Journal of Applied Physics 117, no. 17 (May 7, 2015): 174301.
Version
Author's final manuscript
Abstract
We have computed phonon scattering rates and density of states in silicon germanium alloys using Green's function calculations and density functional theory. This method contrasts with the virtual crystal approximation (VCA) used in conjunction with Fermi's golden rule, which cannot capture resonance states occurring through the interaction of substitutional impurities with the host lattice. These resonances are demonstrated by density of states and scattering rate calculations in the dilute limit and show broadening as the concentration increases. Although these deviations become significant from the VCA at high frequencies, the relaxation times obtained for these phonon modes are small in both the full scattering theory and the VCA, resulting in their negligible contribution to thermal transport.
MIT Department
Massachusetts Institute of Technology. Department of Mechanical Engineering
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Creative Commons Attribution-Noncommercial-Share Alike
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DOI of Published Version
https://doi.org/10.1063/1.4919661
