中国物理B ›› 2017, Vol. 26 ›› Issue (2): 27401-027401.doi: 10.1088/1674-1056/26/2/027401

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Thermal stability and electrical transport properties of Ge/Sn-codoped single crystalline β-Zn4Sb3 prepared by the Sn-flux method

Hong-xia Liu(刘虹霞), Shu-ping Deng(邓书平), De-cong Li(李德聪), Lan-xian Shen(申兰先), Shu-kang Deng(邓书康)   

  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
  • 收稿日期:2016-09-15 修回日期:2016-11-23 出版日期:2017-02-05 发布日期:2017-02-05
  • 通讯作者: Shu-kang Deng E-mail:skdeng@126.com
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 51262032).

Thermal stability and electrical transport properties of Ge/Sn-codoped single crystalline β-Zn4Sb3 prepared by the Sn-flux method

Hong-xia Liu(刘虹霞)1, Shu-ping Deng(邓书平)1, De-cong Li(李德聪)2, Lan-xian Shen(申兰先)1, Shu-kang 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:2016-09-15 Revised:2016-11-23 Online:2017-02-05 Published:2017-02-05
  • Contact: Shu-kang Deng E-mail:skdeng@126.com
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 51262032).

摘要:

This study prepares a group of single crystalline β-Zn4Sb3 with Ge and Sn codoped by the Sn-flux method according to the nominal stoichiometric ratios of Zn4.4Sb3GexSn3 (x=0-0.15). The prepared samples possess a metallic luster surface with perfect appearance and large crystal sizes. The microscopic cracks or defects are invisible in the samples from the back-scattered electron image. Except for the heavily Ge-doped sample of x=0.15, all the samples are single phase with space group R3c. The thermal analysis results show that the samples doped with Ge exhibit an excellent thermal stability. Compared with the polycrystalline Ge-substituted β-Zn4Sb3, the present single crystals have higher carrier mobility, and hence the electrical conductivity is improved, which reaches 7.48×104 S·m-1 at room temperature for the x=0.1 sample. The change of Ge and Sn contents does not improve the Seebeck coefficient significantly. Benefiting from the increased electrical conductivity, the sample with x=0.075 gets the highest power factor of 1.45×10-3 W·m-1·K-2 at 543 K.

关键词: thermoelectric materials, β-Zn4Sb3, flux method, electrical transport properties

Abstract:

This study prepares a group of single crystalline β-Zn4Sb3 with Ge and Sn codoped by the Sn-flux method according to the nominal stoichiometric ratios of Zn4.4Sb3GexSn3 (x=0-0.15). The prepared samples possess a metallic luster surface with perfect appearance and large crystal sizes. The microscopic cracks or defects are invisible in the samples from the back-scattered electron image. Except for the heavily Ge-doped sample of x=0.15, all the samples are single phase with space group R3c. The thermal analysis results show that the samples doped with Ge exhibit an excellent thermal stability. Compared with the polycrystalline Ge-substituted β-Zn4Sb3, the present single crystals have higher carrier mobility, and hence the electrical conductivity is improved, which reaches 7.48×104 S·m-1 at room temperature for the x=0.1 sample. The change of Ge and Sn contents does not improve the Seebeck coefficient significantly. Benefiting from the increased electrical conductivity, the sample with x=0.075 gets the highest power factor of 1.45×10-3 W·m-1·K-2 at 543 K.

Key words: thermoelectric materials, β-Zn4Sb3, flux method, electrical transport properties

中图分类号:  (Thermoelectric effects)

  • 74.25.fg
74.25.fc (Electric and thermal conductivity) 81.10.-h (Methods of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation)