Electronic Structure and Volume Effect on Thermoelectric Transport in P -Type Bi and Sb Tellurides

Author

Minsik Park
Junghwan Song
Julia E. Medvedeva, Missouri University of Science and TechnologyFollow
Miyoung Kim
Ingee Kim
Arthur J. Freeman

Abstract

Thermoelectric transport properties (Seebeck coefficient, S, and electrical conductivity, σ) of p -type Bi and Sb tellurides are investigated using a first-principles all-electron density-functional approach. We demonstrate that the carrier concentration, band gap, and lattice constants have an important influence on the temperature behavior of S and that the volume expansion by 5.5% in Sb₂Te₃ results in an increase in S by 33μV/K at 300 K. We argue that in addition to the electronic structure characteristics, the volume also affects the value of S and hence should be considered as an origin of the experimental observations that S can be enhanced by doping Sb₂Te₃ with Bi (which has a larger ionic size) in Sb sites or by the deposition of thick Bi₂Te₃ layers alternating with thinner Sb₂Te₃ layers in a superlattice, Bi₂Te₃/ Sb₂Te₃. We show that the optimal carrier concentration for the best power factor of Bi₂Te₃ and Sb₂ Te₃ is approximately 10¹⁹ cm^-3

Recommended Citation

M. Park et al., "Electronic Structure and Volume Effect on Thermoelectric Transport in P -Type Bi and Sb Tellurides," Physical review B: Condensed matter and materials physics, vol. 81, no. 15, pp. 155211-1 - 155211-5, American Physical Society (APS), Apr 2010.

The definitive version is available at https://doi.org/10.1103/PhysRevB.81.155211

Department(s)

Physics

International Standard Serial Number (ISSN)

1098-0121

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2010 American Physical Society (APS), All rights reserved.

Publication Date

01 Apr 2010