中国物理B ›› 2020, Vol. 29 ›› Issue (12): 127403-.doi: 10.1088/1674-1056/abbbf5

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  • 收稿日期:2020-07-09 修回日期:2020-09-03 接受日期:2020-09-28 出版日期:2020-12-01 发布日期:2020-12-02

Thermal stability and thermoelectric properties of Cd-doped nano-layered Cu2Se prepared using NaCl flux method

Jianhua Lu(陆建华)1, Decong Li(李德聪)1,2, Wenting Liu(刘文婷)1, Lanxian Shen(申兰先)1, Jiali Chen(陈家莉)1, Wen Ge(葛文)1, and Shukang Deng(邓书康)1,†   

  1. 1 Education Ministry Key Laboratory of Renewable Energy Advanced Materials and Manufacturing Technology, Yunnan Normal University, Kunming 650500, China; 2 Photoelectric Engineering College, Yunnan Open University, Kunming 650500, China
  • Received:2020-07-09 Revised:2020-09-03 Accepted:2020-09-28 Online:2020-12-01 Published:2020-12-02
  • Contact: Corresponding author. E-mail: skdeng@126.com
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 61864012 and 21701140) and the Program for Innovative Research Team (in Science and Technology) in University of Yunnan Province, China.

Abstract: Cu2Se is a promising "phonon liquid-electron crystal" thermoelectric material with excellent thermoelectric performance. In this work, Cd-doped Cu2 -xSeCdx (x = 0, 0.0075, 0.01, and 0.02) samples were prepared using NaCl flux method. The solubility of Cd in Cu2Se at room temperature was less than 6%, and a second phase of CdSe was found in the samples with large initial Cd content (x = 0.01 and 0.02). Field-emission scanning electron microscopic image showed that the arranged lamellae formed a large-scale layered structure with an average thickness of approximately 100 nm. Transmission electron microscopy demonstrated that doping of Cd atoms did not destroy the crystal integrity of Cu2Se. A small amount of Cd in Cu2Se could reduce the electrical and thermal conductivities of the material, thus significantly enhancing its thermoelectric performance. With the increase in Cd content in the sample, the carrier concentration decreased and the mobility increased gradually. Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point. Excessive Cd doping led to the emergence of the second phase of CdSe in the sample, thus significantly increasing the thermal conductivity of the material. A maximum ZT value of 1.67 at 700 K was obtained in the Cu1.9925SeCd0.0075 sample.

Key words: thermoelectric material, Cu2Se doping and second phase, NaCl flux, thermoelectric transfer performance

中图分类号:  (Cuprate superconductors)

  • 74.72.-h
72.20.Pa (Thermoelectric and thermomagnetic effects) 81.30.Hd (Constant-composition solid-solid phase transformations: polymorphic, massive, and order-disorder) 81.16.Nd (Micro- and nanolithography)