High thermoelectric performance via hierarchical compositionally alloyed nanostructures

Li Dong Zhao, Shiqiang Hao, Shih Han Lo, Chun I. Wu, Xiaoyuan Zhou, Yeseul Lee, Hao Li, Kanishka Biswas, Timothy P. Hogan, Ctirad Uher, C. Wolverton, Vinayak P. Dravid, Mercouri G. Kanatzidis*

*Corresponding author for this work

Research output: Contribution to journalArticle

240 Scopus citations

Abstract

Previous efforts to enhance thermoelectric performance have primarily focused on reduction in lattice thermal conductivity caused by broad-based phonon scattering across multiple length scales. Herein, we demonstrate a design strategy which provides for simultaneous improvement of electrical and thermal properties of p-type PbSe and leads to ZT ∼ 1.6 at 923 K, the highest ever reported for a tellurium-free chalcogenide. Our strategy goes beyond the recent ideas of reducing thermal conductivity by adding two key new theory-guided concepts in engineering, both electronic structure and band alignment across nanostructure-matrix interface. Utilizing density functional theory for calculations of valence band energy levels of nanoscale precipitates of CdS, CdSe, ZnS, and ZnSe, we infer favorable valence band alignments between PbSe and compositionally alloyed nanostructures of CdS1-xSe x/ZnS1-xSex. Then by alloying Cd on the cation sublattice of PbSe, we tailor the electronic structure of its two valence bands (light hole L and heavy hole Σ) to move closer in energy, thereby enabling the enhancement of the Seebeck coefficients and the power factor.

Original languageEnglish (US)
Pages (from-to)7364-7370
Number of pages7
JournalJournal of the American Chemical Society
Volume135
Issue number19
DOIs
StatePublished - May 15 2013

ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

Fingerprint Dive into the research topics of 'High thermoelectric performance via hierarchical compositionally alloyed nanostructures'. Together they form a unique fingerprint.

  • Cite this