Materials Transactions Online

Materials Transactions, Vol.53 No.04 (2012) pp.597-600
© 2012 The Japan Institute of Metals

Preparation of n-Type Bi2Te2.85Se0.15 Thermoelectric Semiconductor without Harmful Dopants

Mei Fusa, Natsuki Sumida and Kazuhiro Hasezaki

Department of Materials Science, Faculty of Science and Engineering, Shimane University, Matsue 690-8504, Japan

Undoped n-type Bi2Te2.85Se0.15 compounds without harmful dopants were prepared by mechanical alloying (MA) and sintered by hot pressing (HP). Samples of the Bi2Te3-based materials had a nominal composition of Bi2Te2.85Se0.15. Dopants were not added to control the carrier concentration. The constituent elements, i.e., Bi (5 N), Te (6 N), and Se (5 N), were weighed according to the target composition and milled with silicon-nitride balls. MA was carried out for 30 h. The resulting MA powder was sintered by HP in the temperature range 573-673 K under a mechanical pressure of 147 MPa in an argon atmosphere. The Seebeck coefficient α and electrical conductivity σ were measured in the temperature range 300-473 K. The thermoelectric performance was evaluated from the power factor P, where P = α2σ. The obtained samples exhibited n-type conduction and the single-phase of Bi2(Te, Se)3. The power factor for an undoped sample sintered at 623 K was 4.4 × 10−3 W m−1K−2 at 313 K. This power factor was 88% of the value of 5.0 × 10−3 W m−1K−2 reported for single crystals of n-type doped Bi2Te2.85Se0.15. These results indicated that it is not necessary to dope Bi2Te2.85Se0.15 prepared by an MA-HP process with harmful halide dopants to achieve carrier control.

(Received 2011/09/22; Accepted 2011/12/19; Published 2012/03/25)

Keywords: thermoelectric materials, mechanical alloying, hot pressing, n-type thermoelectric semiconductors, dopants, eco-materials

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REFERENCES

  1. H. Scherrer and S. Scherrer: Thermoelectric Handbook: macro to nano, ed. by D. M. Rowe, (CRC Press, Taylor & Francis Group, 2006) ch27.
  2. N. Fuschillo, J. N. Bierly and F. J. Donahoe: J. Phys. Chem. Solids 8 (1959) 430-433.
  3. K. Uemura and I. Nishida: Thermoelectric Semiconductor and Its Application, (Nikkankogyo Shinbunsha, Tokyo, 1988) pp. 59-88.
  4. J. G. Stockholm, L. Pujol-Soulet and P. Sernat: Proc. 4th ICTEC, (1982) pp. 136-140.
  5. S. Nakajima: J. Phys. Chem. Solids 24 (1963) 479-485.
  6. H. Kaibe, Y. Tanaka, M. Sakata and I. Nishida: J. Phys. Chem. Solids 50 (1989) 945-950.
  7. K. Halada, K. Yamada, K. Ijima and Y. Soeno: J. Japan Inst. Metals 68 (2004) 939-945.
  8. K. Uemura and I. Nishida: Thermoelectric Semiconductor and Its Application, (Nikkankogyo Shinbunsha, Tokyo, 1988) p. 179.
  9. H. T. Kaibe, M. Sakata and I. A. Nishida: J. Phys. Chem. Solids 51 (1990) 1083-1087.
  10. D. Perrin, M. Chitrob, S. Scherrer and H. Scherrer: J. Phys. Chem. Solids 61 (2000) 1687-1691.
  11. L. E. Shelimova, V. S. Zemskov, V. I. Kosyakov and D. V. Malakhov: Inorg. Mater. 30 (1994) 1-8.
  12. M. Sakata: Thermoelectric Conversion, (Syoukabou, Tokyo, 2005) p. 183.
  13. Y. Suga: Nestudennhanndoutai, (Makisyoten, Tokyo, 1966) p. 317.


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