Synthesis of heavily Cu-doped Bi2Te3 nanoparticles and their thermoelectric properties
- 주제(키워드) Bi2Te3 , Doping , Nanoparticle
- 등재 SCIE, SCOPUS
- 발행기관 Academic Press Inc.
- 발행년도 2019
- URI http://www.dcollection.net/handler/ewha/000000155633
- 본문언어 영어
- Published As http://dx.doi.org/10.1016/j.jssc.2018.11.024
- 저작권 이화여자대학교 논문은 저작권에 의해 보호받습니다.
초록/요약
Heavily Cu-doped Bi2Te3 nanoparticles were prepared by intercalating copper metal into flower-like Bi2Te3 nanoparticles using the disproportionation redox reaction of Cu(I) salt. The phase, chemical composition, and morphology of the Bi2Te3 nanoflowers were analyzed by X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). The synthesized Cu-doped Bi2Te3 nanopowders were consolidated by spark-plasma sintering into bulk pellets, and the effects of Cu-doping on the transport properties (electrical resistivity, Seebeck coefficient, and thermal conductivity) of these materials were investigated. Superstoichiometric amounts of Cu (up to ∼28 at%) can be incorporated into flower-like Bi2Te3 nanoparticles, which have large accessible surface area for diffusion of Cu ions. The flower-like morphologies did not change despite high Cu incorporation. Variation in carrier concentration was achieved by changing Cu precursor concentration. Cu-doping in Bi2Te3 can enhance the Seebeck coefficient due to a decrease in carrier concentration, thus the power factors increased compared with that of the un-doped sample. Furthermore, the thermal conductivity of Cu-doped Bi2Te3 is substantially reduced. As a result, Cu-doped Bi2Te3 sample with 15.6 at% Cu exhibited the best thermoelectric performance with a figure of merit of 0.67 at 415 K, which is more than two times higher than that of undoped Bi2Te3 nanopowder. © 2018
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