High-performance tellurium-free thermoelectrics: All-scale hierarchical structuring of p-type PbSe-MSe systems (M = Ca, Sr, Ba)

Yeseul Lee, Shih Han Lo, John Androulakis, Chun I. Wu, Li Dong Zhao, Duck Young Chung, Timothy P. Hogan, Vinayak P. Dravid, Mercouri G. Kanatzidis

Research output: Contribution to journalArticle

104 Citations (Scopus)

Abstract

We present a systematic study of the characterization and thermoelectric properties of nanostructured Na-doped PbSe embedded with 1-4% MSe (M = Ca, Sr, Ba) phases as endotaxial inclusions. The samples were powder-processed by the spark plasma sintering technique, which introduces mesoscale-structured grains. The hierarchical architectures on the atomic scale (Na and M solid solution), nanoscale (MSe nanoprecipitates), and mesoscale (grains) were confirmed by transmission electron microscopy. These structures produce a great reduction in the lattice thermal conductivity relative to pristine PbSe without appreciably affecting the power factor. The lattice thermal conductivity can be reduced by up to ∼29% when the second phase is added. The highest ZT value achieved was ∼1.3 at 923 K for both 2% SrSe-and 3% BaSe-containing samples, while the sample containing 4% CaSe showed a ZT value of ∼1.2 at 923 K. The optimal samples have hole carrier concentration of 1-2 × 1020 cm -3. We attribute the high ZT values to the combination of broad-based phonon scattering on multiple length scales and favorable charge transport through coherent interfaces between the PbSe matrix and MSe.

Original languageEnglish
Pages (from-to)5152-5160
Number of pages9
JournalJournal of the American Chemical Society
Volume135
Issue number13
DOIs
Publication statusPublished - Apr 3 2013

ASJC Scopus subject areas

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

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