Weak electron-phonon coupling contributing to high thermoelectric performance in n-type PbSe

Heng Wang, Yanzhong Pei*, Aaron D. LaLonde, G. Jeffrey Snyder

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

293 Scopus citations

Abstract

PbSe is a surprisingly good thermoelectric material due, in part, to its low thermal conductivity that had been overestimated in earlier measurements. The thermoelectric figure of merit, zT, can exceed 1 at high temperatures in both p-type and n-type PbSe, similar to that found in PbTe. While the p-type lead chalcogenides (PbSe and PbTe) benefit from the high valley degeneracy (12 or more at high temperature) of the valence band, the n-type versions are limited to a valley degeneracy of 4 in the conduction band. Yet the n-type lead chalcogenides achieve a zT nearly as high as the p-type lead chalcogenides. This effect can be attributed to the weaker electron-phonon coupling (lower deformation potential coefficient) in the conduction band as compared with that in the valence band, which leads to higher mobility of electrons compared to that of holes. This study of PbSe illustrates the importance of the deformation potential coefficient of the charge-carrying band as one of several key parameters to consider for band structure engineering and the search for high performance thermoelectric materials.

Original languageEnglish (US)
Pages (from-to)9705-9709
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue number25
DOIs
StatePublished - Jun 19 2012

Keywords

  • Energy
  • Quality factor
  • Semiconductor

ASJC Scopus subject areas

  • General

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