Enhancement of thermoelectric performance by tuning selenium content in the Cu2SnSe3 compound

K. Gurukrishna, Ashok Rao, Zhao Ze Jiang, Yung Kang Kuo

Research output: Contribution to journalArticle

Abstract

To investigate the thermoelectric properties, we have attempted to tune selenium content in Cu2SnSe3-δ (−0.04 ≤ δ ≤ 0.1) compounds synthesized via the conventional solid-state reaction. Electrical and thermal properties are presented in the low and near room temperature regime (10–350 K). The lowest electrical resistivity is observed for the compound with δ = 0.08. The electron-phonon coupling and the presence of small polarons are experimentally validated from temperature-dependent electrical and thermal transport data. A decrease in the Seebeck coefficient along with carrier concentration is observed, verifying the linear electron band dispersion. A downward shift of the Fermi level deep into the valence band is realized in the case of non-stoichiometric samples, thereby reducing the Seebeck coefficient. A maximum power factor of ~50 μWmK−2 is achieved for the sample with δ = 0.04, which is about twice that of the pristine compound. The highest ZT of ~0.01 is obtained for the compound with δ = 0.08. The observed results suggest that stoichiometry plays a vital role in tuning the thermoelectric properties in the Cu2SnSe3 compound.

Original languageEnglish
Article number106803
JournalIntermetallics
Volume122
DOIs
Publication statusPublished - 07-2020

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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