Vacancy-induced dislocations within grains for high-performance PbSe thermoelectrics

Zhiwei Chen, Binghui Ge, Wen Li, Siqi Lin, Jiawen Shen, Yunjie Chang, Riley Hanus, G. Jeffrey Snyder, Yanzhong Pei*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

232 Scopus citations

Abstract

To minimize the lattice thermal conductivity in thermoelectrics, strategies typically focus on the scattering of low-frequency phonons by interfaces and high-frequency phonons by point defects. In addition, scattering of mid-frequency phonons by dense dislocations, localized at the grain boundaries, has been shown to reduce the lattice thermal conductivity and improve the thermoelectric performance. Here we propose a vacancy engineering strategy to create dense dislocations in the grains. In Pb1-x Sb2x/3 Se solid solutions, cation vacancies are intentionally introduced, where after thermal annealing the vacancies can annihilate through a number of mechanisms creating the desired dislocations homogeneously distributed within the grains. This leads to a lattice thermal conductivity as low as 0.4 Wm-1 K-1 and a high thermoelectric figure of merit, which can be explained by a dislocation scattering model. The vacancy engineering strategy used here should be equally applicable for solid solution thermoelectrics and provides a strategy for improving zT.

Original languageEnglish (US)
Article number13828
JournalNature communications
Volume8
DOIs
StatePublished - Jan 4 2017

ASJC Scopus subject areas

  • Chemistry(all)
  • Biochemistry, Genetics and Molecular Biology(all)
  • Physics and Astronomy(all)

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