Effect of Composition Adjustment on the Thermoelectric Properties of Mg3Bi2-Based Thermoelectric Materials

Jianbao Yang; Zhibin Wang; Hong Zhao; Xinyu Luo; Wenyuan Han; Hao Wang; Linghao Meng; Xinqi She; Anlong Quan; Yixin Peng; Guoji Cai; Yi Liu; Yong Tang; Bo Feng

doi:10.3390/mi14101844

Effect of Composition Adjustment on the Thermoelectric Properties of Mg₃Bi₂-Based Thermoelectric Materials

Micromachines (Basel). 2023 Sep 27;14(10):1844. doi: 10.3390/mi14101844.

Authors

Jianbao Yang¹, Zhibin Wang¹, Hong Zhao¹, Xinyu Luo¹, Wenyuan Han¹, Hao Wang¹, Linghao Meng¹, Xinqi She¹, Anlong Quan¹, Yixin Peng¹, Guoji Cai², Yi Liu², Yong Tang², Bo Feng^{1

2

3}

Affiliations

¹ Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning 437100, China.
² School of Mechanical and Electrical Engineering, Wuhan Donghu University, Wuhan 430070, China.
³ The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, China.

Abstract

Thermoelectric materials are widely used in refrigeration chips, thermal power generation, catalysis and other fields. Mg₃Bi₂-based thermoelectric material is one of the most promising thermoelectric materials. Herein, the Mg₃Bi₂-based samples were prepared by high temperature synthesis, and the influence of Mg/Sb content on the electrical transport properties and semi-conductivity/semi-metallicity of the materials has been studied. The results indicate that the efficiency of introducing electrons from excess Mg prepared by high temperature synthesis is lower than that introduced by ball milling, due to the high vapor pressure of Mg. The doping of Sb/Te at the Bi site would make it easier for the material to change from p-type conduction to n-type conduction. With the increase in Mg content, the semi-conductivity of the material becomes weaker, the semi-metallicity becomes stronger, and the corresponding conductivity increases. With the increase in Sb content, the samples exhibit the opposite changes. The highest power factor of ~1.98 mWm^-1K^-2 is obtained from the Mg_3.55Bi_1.27Sb_0.7Te_0.03 sample.

Keywords: Mg3Bi2; acceptor effect; composition adjustment; thermoelectric properties.

Grants and funding

The work is supported by the Natural Science Foundation of Hubei Province (2021CFB009), the guiding project of Hubei Province in 2022 (B2022313), Hundred Talents Plan Project of Xianning City in Hubei Province and the School Youth Fund of Wuhan Donghu University.