Optimal Bandwidth for High Efficiency Thermoelectrics
Name
Zhou-2011-Optimal Bandwidth for High Efficiency Thermoelectrics.pdf
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690.27 KB
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Checksum (MD5)
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Author(s)
Zhou, Jun
Yang, Ronggui
Chen, Gang
Dresselhaus, Mildred
Date Issued
November 2011
Journal
Physical Review Letters
Publisher
American Physical Society (APS)
Citation
Zhou, Jun et al. “Optimal Bandwidth for High Efficiency Thermoelectrics.” Physical Review Letters 107.22 (2011): n. pag. Web. 9 Mar. 2012. © 2011 American Physical Society
Version
Final published version
Abstract
The thermoelectric figure of merit (ZT) in narrow conduction bands of different material dimensionalities is investigated for different carrier scattering models. When the bandwidth is zero, the transport distribution function (TDF) is finite, not infinite as previously speculated by Mahan and Sofo [ Proc. Natl. Acad. Sci. U.S.A. 93 7436 (1996)], even though the carrier density of states goes to infinity. Such a finite TDF results in a zero electrical conductivity and thus a zero ZT. We point out that the optimal ZT cannot be found in an extremely narrow conduction band. The existence of an optimal bandwidth for a maximal ZT depends strongly on the scattering models and the dimensionality of the material. A nonzero optimal bandwidth for maximizing ZT also depends on the lattice thermal conductivity. A larger maximum ZT can be obtained for materials with a smaller lattice thermal conductivity.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Massachusetts Institute of Technology. Department of Mechanical Engineering
Massachusetts Institute of Technology. Department of Physics
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Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1103/PhysRevLett.107.226601
