Crystals (Jun 2020)

Effect of Deposition Power on the Thermoelectric Performance of Bismuth Telluride Prepared by RF Sputtering

  • Kai-Yan Zang,
  • Er-Tao Hu,
  • Zheng-Yong Wang,
  • Hua-Tian Tu,
  • Yu-Xiang Zheng,
  • Song-You Wang,
  • Hai-Bin Zhao,
  • Yue-Mei Yang,
  • Young-Pak Lee,
  • Liang-Yao Chen

DOI
https://doi.org/10.3390/cryst10070552
Journal volume & issue
Vol. 10, no. 7
p. 552

Abstract

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In this work, we present a simple method to improve the thermoelectric performance of the RF sputtered bismuth telluride films by raising the power of deposition. The as-deposited samples synthesized under different powers were investigated and compared. It shows that the films prepared under relatively higher power conditions exhibit much higher electrical conductivity to result in a greater power factor accompanied with a minor drop in the Seebeck coefficients. A relationship is established between the improvement in thermoelectric performance and the decrease in crystallinity, which might also reduce the thermal conductivity. A maximum power factor of 5.65 × 10−4 W·m−1·K−2 at 470 K is obtained for the sample deposited under 50 W with its Seebeck coefficient being −105 μV/K. The temperature-dependent behaviors of the samples are also looked into and discussed. This work might offer an in-situ and cost-effective approach to improve the performance of thermoelectric materials.

Keywords