Enhancement in thermoelectric properties of Te-embedded Bi2Te3 by preferential phonon scattering in heterostructure interface

Hyejin Choi, Kwangsik Jeong, Jimin Chae, Hanbum Park, Juheyuck Baeck, Tae Hyeon Kim, Jae Yong Song, Jaehun Park, Kwang Ho Jeong, Mann Ho Cho

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

A comprehensive understanding of the nano-structural effects that cause reduction in thermal conductivity represents important challenges for the development of thermoelectric materials with an improved figure of merit ZT. Bismuth telluride (Bi2Te3)-based thermoelectric materials exhibit very low levels of thermal conductivity. In this study, a Te crystal-embedded Bi2Te3 (Te–Bi2Te3) thin film was formed by establishing a specific annealing temperature for a Te-rich Bi/Te multilayered structure. Modulations in structure and composition were observed at the boundaries between the two phases of Te and Bi2Te3. Furthermore, the samples contained regularly shaped nanometer-scale Bi2Te3 single grains. Therefore, we obtained a dramatic ZT value of 2.27 (+ 0.04, − 0.08) at 375 K from the Te–Bi2Te3 thin film. Finally, we confirmed that interface phonon scattering between the Te–Bi2Te3 boundaries plays an important role in inter-grain phonon transport, which results in a reduction in the lattice thermal conductivity.

Original languageEnglish
Pages (from-to)374-384
Number of pages11
JournalNano Energy
Volume47
DOIs
Publication statusPublished - 2018 May

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Materials Science(all)
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'Enhancement in thermoelectric properties of Te-embedded Bi<sub>2</sub>Te<sub>3</sub> by preferential phonon scattering in heterostructure interface'. Together they form a unique fingerprint.

  • Cite this