Enhanced Thermoelectric Performance of Cu-incorporated Bi0.5Sb1.5Te3 by Melt Spinning and Spark Plasma Sintering

Hyun jun Cho, Hyun sik Kim, Minyoung Kim, Kyu Hyoung Lee, Sung Wng Kim, Sang il Kim

Research output: Contribution to journalArticle

Abstract

Incorporation of a foreign element is considered as a promising approach to enhance the performance of thermoelectric materials since this can either improve the power factor by a band structure modification or reduce the thermal conductivity by a phonon scattering strengthening. We fabricated the polycrystalline bulk samples of Cu-incorporated Bi0.5Sb1.5Te3 by melt spinning and spark plasma sintering, and evaluated the electronic and thermal transport properties. From the phase analysis and thermoelectric properties measurement, we found that most of the added excess Cu atoms were substituted at a Sb-site and a small amount of Cu was intercalated at the van der Waals gap between quintuple layers. By the formation of two different point defects (substituted Cu and intercalated Cu), the thermoelectric power factor was enhanced because of the increased density of states effective mass, and simultaneously reduced thermal conductivity originated from the intensified phonon scattering and suppressed bipolar contribution. Maximum thermoelectric figure of merit zT of 1.13 was obtained at 400 K.

Original languageEnglish
JournalJournal of Electronic Materials
DOIs
Publication statusAccepted/In press - 2019 Jan 1

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All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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