Journal of Inorganic Materials ›› 2023, Vol. 38 ›› Issue (2): 163-169.DOI: 10.15541/jim20220106

• RESEARCH ARTICLE • Previous Articles     Next Articles

Effect of Surface Treatment of n-type Bi2Te3-based Materials on the Properties of Thermoelectric Units

HUA Siheng(), YANG Dongwang, TANG Hao, YUAN Xiong, ZHAN Ruoyu, XU Zhuoming, LYU Jianan, XIAO Yani, YAN Yonggao(), TANG Xinfeng()   

  1. State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
  • Received:2022-03-02 Revised:2022-05-09 Published:2023-02-20 Online:2022-05-27
  • Contact: YAN Yonggao, professor. E-mail:;
    TANG Xinfeng, professor. E-mail:
  • About author:HUA Siheng (1997-), male, Master candidate. E-mail:
  • Supported by:
    National Key Research and Development Program of China(2019YFA0704900)


The smaller the size of the Bi2Te3-based micro thermoelectric device, the more significant the effect of interface bonding strength and contact resistance on the mechanical properties, open circuit voltage and output power of the device. It is of great significance to develop a thermoelectric unit preparation technology with low cost and simple process, and to enable the interface between n-type Bi2Te3 bulk materials and barrier layer with low contact resistance and high bonding strength. Here, surface of n-type Bi2Te3-based thermoelectric material was treated in mixed acid solution (pH~3), followed by electroless plating Ni (5 μm), and then welded with Cu electrode to prepare thermoelectric unit. After corrosion, the anchoring effect between large gully on the surface of n-type Bi2Te3-based thermoelectric materials and Ni barrier layer contributes to the interface bonding strength of 15.88 MPa for the material corroded for 6 min. Furthermore, nano-holes between the Ni barrier layer and the fine branches corroded by further corrosion significantly increase the interface contact resistance, resulting in 2.23 μΩ·cm2 for the material corroded for 2 min. Finally, the output power of the micro thermoelectric device prepared by n-type Bi2Te3-based bulk material for 4 min corrosion treatment is as high as 3.43 mW at 20 K temperature difference (306 K at high temperature end and 286 K at low temperature end). Compared to device with the same size prepared by commercial electroplating coating, the output power is increased by 31.92%. This work provides support to optimize the performance of micro thermoelectric devices.

Key words: Bi2Te3, interface bonding strength, interface contact resistance, Ni barrier layer, micro thermoelectric device

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