N-Type Bi2Te3-xSex Nanoplates with Enhanced Thermoelectric Efficiency Driven by Wide-Frequency Phonon Scatterings and Synergistic Carrier Scatterings

Min Hong, Thomas C. Chasapis, Zhi Gang Chen*, Lei Yang, Mercouri Kanatzidis, Gerald Jeffrey Snyder, Jin Zou

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

175 Scopus citations

Abstract

Driven by the prospective applications of thermoelectric materials, massive efforts have been dedicated to enhancing the conversion efficiency. The latter is governed by the figure of merit (ZT), which is proportional to the power factor (S2σ) and inversely proportional to the thermal conductivity (κ). Here, we demonstrate the synthesis of high-quality ternary Bi2Te3-xSex nanoplates using a microwave-assisted surfactant-free solvothermal method. The obtained n-type Bi2Te2.7Se0.3 nanostructures exhibit a high ZT of 1.23 at 480 K measured from the corresponding sintered pellets, in which a remarkably low κ and a shift of peak S2σ to high temperature are observed. By detailed electron microscopy investigations, coupled with theoretical analysis on phonon transports, we propose that the achieved κ reduction is attributed to the strong wide-frequency phonon scatterings. The shifting of peak S2σ to high temperature is due to the weakened temperature dependent transport properties governed by the synergistic carrier scatterings and the suppressed bipolar effects by enlarging the band gap.

Original languageEnglish (US)
Pages (from-to)4719-4727
Number of pages9
JournalACS nano
Volume10
Issue number4
DOIs
StatePublished - Apr 26 2016

Keywords

  • BiTeSe
  • nanostructuring
  • synergistic carrier scatterings
  • thermoelectric
  • wide-frequency phonon scatterings

ASJC Scopus subject areas

  • Materials Science(all)
  • Engineering(all)
  • Physics and Astronomy(all)

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