Band structure engineering in highly degenerate tetrahedrites through isovalent doping

Xu Lu; Wei Yao; Guiwen Wang; Xiaoyuan Zhou; Donald Morelli; Yongsheng Zhang; Hang Chi; Si Hui; Ctirad Uher

doi:10.1039/C6TA07015A

Band structure engineering in highly degenerate tetrahedrites through isovalent doping†

Xu Lu,*^a Wei Yao,^a Guiwen Wang,^b Xiaoyuan Zhou,*^ab Donald Morelli,^c Yongsheng Zhang,*^d Hang Chi,^e Si Hui^e and Ctirad Uher^e

Author affiliations

* Corresponding authors

^a College of Physics, Chongqing University, Chongqing 401331, P. R. China
E-mail: luxu@cqu.edu.cn, xiaoyuan2013@cqu.edu.cn

^b Analytical and Testing Center of Chongqing University, Chongqing 401331, P. R. China

^c Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing, Michigan 48824, USA

^d Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031, P. R. China
E-mail: yshzhang@theory.issp.ac.cn

^e Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA

Abstract

It can be difficult to reduce the electrical resistivity of highly degenerate semiconductors due to their high carrier concentration, impeding the further increase in their thermoelectric power factor. Here we report on an enhancement in the power factor of highly degenerate Cu₁₂Sb₄S_13−xSe_x solid solutions, which show a dramatic decrease in the electrical resistivity while maintaining a constant Seebeck coefficient for various contents of Se. Rather than arising from an increased carrier concentration, the reduced electrical resistivity is a consequence of the upward displacement of the valence bands with low effective masses. Using theoretical calculations, we show that these additional valence bands have a similar density of states effective mass to that of the existing conduction valley, thus yielding unchanged Seebeck coefficients. The results suggest that the power factor of highly degenerate semiconductors can be enhanced through careful band structure engineering via isovalent doping.

Supplementary files

Article information

DOI: https://doi.org/10.1039/C6TA07015A
Article type: Paper
Submitted: 16 Aug 2016
Accepted: 30 Sep 2016
First published: 03 Oct 2016

Download Citation

J. Mater. Chem. A, 2016,4, 17096-17103

Permissions

Request permissions

Band structure engineering in highly degenerate tetrahedrites through isovalent doping

X. Lu, W. Yao, G. Wang, X. Zhou, D. Morelli, Y. Zhang, H. Chi, S. Hui and C. Uher, J. Mater. Chem. A, 2016, 4, 17096 DOI: 10.1039/C6TA07015A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Journal of Materials Chemistry A

Band structure engineering in highly degenerate tetrahedrites through isovalent doping†

Abstract

Supplementary files

Article information

Download Citation

Permissions

Band structure engineering in highly degenerate tetrahedrites through isovalent doping

Social activity

Search articles by author

Spotlight

Advertisements