J. Mater. Sci. Technol. ›› 2022, Vol. 127: 108-114.DOI: 10.1016/j.jmst.2022.02.054

• Research Article • Previous Articles     Next Articles

Enhanced thermoelectric performance in n-type Mg3.2Sb1.5Bi0.5 doping with lanthanides at the Mg site

Lu Yua, Zipei Zhanga, Juan Lia, Wenhao Lia, Shikai Weia, Sitong Weia, Guiwu Lub, Weiyu Songb, Shuqi Zhenga,*()   

  1. aState Key Laboratory of Heavy Oil Processing, College of New Energy and Materials, China University of Petroleum, Beijing 102249, China
    bCollege of Science, China University of Petroleum, Beijing 102249, China
  • Received:2021-11-05 Revised:2021-12-13 Accepted:2022-02-18 Published:2022-11-10 Online:2022-11-10
  • Contact: Shuqi Zheng
  • About author:* E-mail address: zhengsq09@163.com (S. Zheng)

Abstract:

Mg-based thermoelectric materials have attracted more and more attention because of their rich composition elements, green environmental protection, and lower price. In recent years, the thermoelectric properties of n-type Mg3Sb2 materials have been optimized by doping chalcogenide elements (S, Se, and Te) at the anionic position. In this work, n-type Mg3.2AxSb1.5Bi0.5 (A = Gd, Ho; x = 0.01, 0.02, 0.03, and 0.4) samples were prepared by the cation site doping of lanthanide elements (Gd and Ho). The research results show that Gd and Ho doped n-type Mg3.2Sb1.5Bi0.5 samples are entirely comparable to the S, Se, and Te doped n-type Mg3.2Sb1.5Bi0.5 samples, demonstrating more excellent thermoelectric properties. Doping with lanthanides (Gd and Ho) at the Mg site increases the carrier concentration of the material to 8.161 × 1019 cm−3. Doping induces the contribution of more electron, thus obtaining higher conductivity. The maximum zT value of the Mg3.2Gd0.02Sb1.5Bi0.5 and the Mg3.2Ho0.02Sb1.5Bi0.5 samples reaches 1.61 and 1.55, respectively. This work theoretically and experimentally demonstrates Gd and Ho are efficient n-type dopants for Mg3.2Sb1.5Bi0.5 thermoelectric material.

Key words: Thermoelectric material, First-principles calculation, Mg3.2Sb1.5Bi0.5