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The Thermoelectric Properties of n-Type Bismuth Telluride: Bismuth Selenide Alloys Bi2Te3−xSex

Authors :
Ian T. Witting
Francesco Ricci
Thomas C. Chasapis
Geoffroy Hautier
G. Jeffrey Snyder
Source :
Research, Vol 2020 (2020)
Publication Year :
2020
Publisher :
American Association for the Advancement of Science (AAAS), 2020.

Abstract

Alloying bismuth telluride with antimony telluride and bismuth selenide for p- and n-type materials, respectively, improves the thermoelectric quality factor for use in room temperature modules. As the electronic and thermal transports can vary substantially, the alloy composition is a key engineering parameter. The n-type Bi2Te3-xSex alloy lags its p-type counterpart in thermoelectric performance and does not lend itself as readily to simple transport modeling which complicates engineering. Combining literature data with recent results across the entire alloy composition range, the complex electronic structure dynamics and trends in lattice thermal conductivity are explored. Spin-orbit interaction plays a critical role in determining the position and degeneracy of the various conduction band minima. This behavior is incorporated into a two-band effective mass model to estimate the transport parameters in each band. An alloy scattering model is utilized to demonstrate how phonon scattering behaves differently on either side of the intermediate ordered compound Bi2Te2Se due to chalcogen site occupancy preference. The parametrization of the electronic and thermal transports presented can be used in future optimization efforts.

Subjects

Subjects :
Science

Details

Language :
English
ISSN :
26395274
Volume :
2020
Database :
Directory of Open Access Journals
Journal :
Research
Publication Type :
Academic Journal
Accession number :
edsdoj.3779a4c40e44485693da7b3eb567ab26
Document Type :
article
Full Text :
https://doi.org/10.34133/2020/4361703