Control of p-type and n-type thermoelectric properties of bismuth telluride thin films by combinatorial sputter coating technology

Masahiro Goto, Michiko Sasaki, Yibin Xu, Tianzhuo Zhan, Yukihiro Isoda, Yoshikazu Shinohara

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

p- and n-type bismuth telluride thin films have been synthesized by using a combinatorial sputter coating system (COSCOS). The crystal structure and crystal preferred orientation of the thin films were changed by controlling the coating condition of the radio frequency (RF) power during the sputter coating. As a result, the p- and n-type films and their dimensionless figure of merit (ZT) were optimized by the technique. The properties of the thin films such as the crystal structure, crystal preferred orientation, material composition and surface morphology were analyzed by X-ray diffraction, energy-dispersive X-ray spectroscopy and atomic force microscopy. Also, the thermoelectric properties of the Seebeck coefficient, electrical conductivity and thermal conductivity were measured. ZT for n- and p-type bismuth telluride thin films was found to be 0.27 and 0.40 at RF powers of 90 and 120 W, respectively. The proposed technology can be used to fabricate thermoelectric p–n modules of bismuth telluride without any doping process.

Original languageEnglish
Pages (from-to)405-411
Number of pages7
JournalApplied Surface Science
Volume407
DOIs
Publication statusPublished - 2017 Jun 15
Externally publishedYes

    Fingerprint

Keywords

  • Bismuth telluride
  • Coating
  • Combinatorial
  • Sputter
  • Thermoelectric conversion
  • Thin film

ASJC Scopus subject areas

  • Surfaces, Coatings and Films

Cite this