Effect of electron-phonon interaction on lattice thermal conductivity of SiGe alloys
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effect of electron.pdf
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1.79 MB
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Checksum (MD5)
9387b2e7039d7e30396ae0db92b068a1
Author(s)
Xu, Qian
Zhou, Jiawei
Liu, Te-Huan
Chen, Gang
Date Issued
July 2019
Journal
Applied Physics Letters
Publisher
AIP Publishing
Citation
Xu, Qian et al. "Effect of electron-phonon interaction on lattice thermal conductivity of SiGe alloys." Applied Physics Letters 115, 2 (July 2019): 023903.
Version
Author's final manuscript
Abstract
While it is well-known that electron-phonon scattering often determines the electron mobility, its impact on lattice thermal conductivity is less clear. Dominant phonon scattering mechanisms that determine the lattice thermal conductivity have been attributed to phonon-phonon and phonon-defect interactions. However, recent studies in silicon have shown that strong electron-phonon interaction can also lead to significant phonon scatterings at high carrier concentrations. Here, we use first-principles simulations to study thermal transport in SiGe alloys and show that the effect of electron-phonon interaction on thermal transport is even more significant than that in Si because mass disorder scattering leaves long mean free path phonons behind, which are more strongly scattered by electrons. At the carrier concentration of 1 × 10[superscript 20]cm[superscript −3], the room temperature lattice thermal conductivity of the Si[subscript 0.9]Ge[subscript 0.1] alloy including electron-phonon interaction is only 40% of the value without this interaction. The results show that thermal transport in alloys at a high doping level can be significantly impacted by the free carriers, providing important insights into heat conduction mechanisms in thermoelectric materials which are mostly based on heavily doped alloys.
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/10.1063/1.5108836
