Enhanced thermoelectric figure-of-merit in thermally robust, nanostructured superlattices based on SrTiO3

Anas I. Abutaha, S. R. Sarath Kumar, Kun Li, Arash Mehdizadeh Dehkordi, Terry M. Tritt, Husam N. Alshareef

Research output: Contribution to journalArticlepeer-review

26 Scopus citations

Abstract

Thermoelectric (TE) metal oxides overcome crucial disadvantages of traditional heavy-metal-alloy-based TE materials, such as toxicity, scarcity, and instability at high temperatures. Here, we report the TE properties of metal oxide superlattices, composed from alternating layers of 5% Pr3+-doped SrTiO3-δ (SPTO) and 20% Nb5+-doped SrTiO3-δ (STNO) fabricated using pulsed laser deposition (PLD). Excellent stability is established for these superlattices by maintaining the crystal structure and reproducing the TE properties after long-time (20 h) annealing at high temperature (∼1000 K). The introduction of oxygen vacancies as well as extrinsic dopants (Pr3+ and Nb5+), with different masses and ionic radii, at different lattice sites in SPTO and STNO layers, respectively, results in a substantial reduction of thermal conductivity via scattering a wider range of phonon spectrum without limiting the electrical transport and thermopower, leading to an enhancement in the figure-of-merit (ZT). The superlattice composed of 20 SPTO/STNO pairs, 8 unit cells of each layer, exhibits a ZT value of 0.46 at 1000 K, which is the highest among SrTiO3-based thermoelectrics. © 2015 American Chemical Society.
Original languageEnglish (US)
Pages (from-to)2165-2171
Number of pages7
JournalChemistry of Materials
Volume27
Issue number6
DOIs
StatePublished - Mar 9 2015

ASJC Scopus subject areas

  • Materials Chemistry
  • Chemical Engineering(all)
  • Chemistry(all)

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