中国物理B ›› 2017, Vol. 26 ›› Issue (6): 66103-066103.doi: 10.1088/1674-1056/26/6/066103

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Electronic and thermoelectric properties of Mg2GexSn1-x (x=0.25, 0.50, 0.75) solid solutions by first-principles calculations

Kai-yue Li(李开跃), Yong Lu(鲁勇), Yan Huang(黄艳), Xiao-hong Shao(邵晓红)   

  1. College of Science, Beijing University of Chemical Technology, Beijing 100029, China
  • 收稿日期:2017-01-18 修回日期:2017-03-04 出版日期:2017-06-05 发布日期:2017-06-05
  • 通讯作者: Yong Lu, Xiao-hong Shao E-mail:luy@mail.buct.edu.cn;shaoxh@mail.buct.edu.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant No. 11647010) and the Foundation from the Higher Education and High-quality and World-class Universities (Grant No. PY201611).

Electronic and thermoelectric properties of Mg2GexSn1-x (x=0.25, 0.50, 0.75) solid solutions by first-principles calculations

Kai-yue Li(李开跃), Yong Lu(鲁勇), Yan Huang(黄艳), Xiao-hong Shao(邵晓红)   

  1. College of Science, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:2017-01-18 Revised:2017-03-04 Online:2017-06-05 Published:2017-06-05
  • Contact: Yong Lu, Xiao-hong Shao E-mail:luy@mail.buct.edu.cn;shaoxh@mail.buct.edu.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant No. 11647010) and the Foundation from the Higher Education and High-quality and World-class Universities (Grant No. PY201611).

摘要:

The electronic structure and thermoelectric (TE) properties of Mg2GexSn1-x (x=0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special quasi-random structure (SQS) is used to model the solid solutions, which can produce reasonable band gaps with respect to experimental results. The n-type solid solutions have an excellent thermoelectric performance with maximum zT values exceeding 2.0, where the combination of low lattice thermal conductivity and high power factor (PF) plays an important role. These values are higher than those of pure Mg2Sn and Mg2Ge. The p-type solid solutions are inferior to the n-type ones, mainly due to the much lower PF. The maximum zT value of 0.62 is predicted for p-type Mg2Ge0.25Sn0.75 at 800 K. The results suggest that the n-type Mg2GexSn1-x solid solutions are promising mid-temperature TE materials.

关键词: solid solution, electronic structure, thermoelectric transport property

Abstract:

The electronic structure and thermoelectric (TE) properties of Mg2GexSn1-x (x=0.25, 0.50, 0.75) solid solutions are investigated by first-principles calculations and semi-classical Boltzmann theory. The special quasi-random structure (SQS) is used to model the solid solutions, which can produce reasonable band gaps with respect to experimental results. The n-type solid solutions have an excellent thermoelectric performance with maximum zT values exceeding 2.0, where the combination of low lattice thermal conductivity and high power factor (PF) plays an important role. These values are higher than those of pure Mg2Sn and Mg2Ge. The p-type solid solutions are inferior to the n-type ones, mainly due to the much lower PF. The maximum zT value of 0.62 is predicted for p-type Mg2Ge0.25Sn0.75 at 800 K. The results suggest that the n-type Mg2GexSn1-x solid solutions are promising mid-temperature TE materials.

Key words: solid solution, electronic structure, thermoelectric transport property

中图分类号:  (Structure of bulk crystals)

  • 61.50.-f
74.25.fc (Electric and thermal conductivity)