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

Research output: Contribution to journalArticle

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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 Cu12Sb4S13-xSex 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.

LanguageEnglish (US)
Pages17096-17103
Number of pages8
JournalJournal of Materials Chemistry A
Volume4
Issue number43
DOIs
StatePublished - 2016

Profile

Seebeck coefficient
Valence bands
Band structure
Carrier concentration
Doping (additives)
Semiconductor materials
Thermoelectric power
Solid solutions

ASJC Scopus subject areas

  • Chemistry(all)
  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)

Cite this

Band structure engineering in highly degenerate tetrahedrites through isovalent doping. / Lu, Xu; Yao, Wei; Wang, Guiwen; Zhou, Xiaoyuan; Morelli, Donald; Zhang, Yongsheng; Chi, Hang; Hui, Si; Uher, Ctirad.

In: Journal of Materials Chemistry A, Vol. 4, No. 43, 2016, p. 17096-17103.

Research output: Contribution to journalArticle

Lu, X, Yao, W, Wang, G, Zhou, X, Morelli, D, Zhang, Y, Chi, H, Hui, S & Uher, C 2016, 'Band structure engineering in highly degenerate tetrahedrites through isovalent doping' Journal of Materials Chemistry A, vol 4, no. 43, pp. 17096-17103. DOI: 10.1039/c6ta07015a
Lu, Xu ; Yao, Wei ; Wang, Guiwen ; Zhou, Xiaoyuan ; Morelli, Donald ; Zhang, Yongsheng ; Chi, Hang ; Hui, Si ; Uher, Ctirad. / Band structure engineering in highly degenerate tetrahedrites through isovalent doping. In: Journal of Materials Chemistry A. 2016 ; Vol. 4, No. 43. pp. 17096-17103
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