A two-step synthesis process of thermoelectric alloys for the separate control of carrier density and mobility

Sang Soon Lim, Byung Kyu Kim, Seong Keun Kim, Hyung-Ho Park, Dong Ik Kim, Dow Bin Hyun, Jin Sang Kim, Seung Hyub Baek

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

It is challenging to improve the thermoelectric figure-of-merit as its constituent terms such as Seebeck coefficient, electrical conductivity, and thermal conductivity, are inter-related in the way that the enhancement of one term leads to the degradation of others. Therefore, it is highly desirable to design a new synthesis process that allows us to independently control these terms. Here, we report a simple, two-step process combining spark plasma sintering (SPS) and post-annealing (PA) to separately control the carrier density and mobility in the p-type (Bi 0.2 Sb 0.8 ) 2 Te 3 . High-temperature SPS enables enhancing the carrier mobility by reducing scattering sites such as grain boundaries. Then, the following PA at a lower temperature allows tailoring the carrier density without the degradation of mobility. Beyond bismuth telluride-based, room-temperature thermoelectric materials, we believe that our result will provide an insight for the performance enhancement of other thermoelectric materials such as oxide and skutterudite.

Original languageEnglish
Pages (from-to)191-195
Number of pages5
JournalJournal of Alloys and Compounds
Volume727
DOIs
Publication statusPublished - 2017 Dec 15

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All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

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