Realizing a High ZT of 1.6 in N-Type Mg3Sb2-Based Zintl Compounds through Mn and Se Codoping

Jisheng Liang; Hengquan Yang; Chengyan Liu; Lei Miao; Junliang Chen; Sijing Zhu; Zhengchuan Xie; Wenjing Xu; Xiaoyang Wang; Jun Wang; Biaolin Peng; Kunihito Koumoto

doi:10.1021/acsami.0c01004

Realizing a High ZT of 1.6 in N-Type Mg₃Sb₂-Based Zintl Compounds through Mn and Se Codoping

ACS Appl Mater Interfaces. 2020 May 13;12(19):21799-21807. doi: 10.1021/acsami.0c01004. Epub 2020 Apr 29.

Authors

Jisheng Liang¹, Hengquan Yang², Chengyan Liu¹, Lei Miao^{1

3}, Junliang Chen⁴, Sijing Zhu¹, Zhengchuan Xie¹, Wenjing Xu¹, Xiaoyang Wang^{1

5}, Jun Wang⁶, Biaolin Peng³, Kunihito Koumoto^{7

8}

Affiliations

¹ Guangxi Key Laboratory of Information Material, Guangxi Collaborative Innovation Center of Structure and Property for New Energy and Materials, School of Material Science and Engineering, Guilin University of Electronic Technology, Guilin 541004, P. R. China.
² School of Physics and Electronic & Electrical Engineering, and Jiangsu Key Laboratory of Modern Measurement Technology and Intelligent Systems, Huaiyin Normal University, Huai'an 223300, P. R. China.
³ Center on Nanoenergy Research, Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials, Guangxi Key Laboratory for Relativity Astrophysics, School of Physical Science & Technology, Guangxi University, Nanning 530004, P. R. China.
⁴ School of Chemistry and Chemical Engineering, Guangxi University, Nanning 530004, P. R. China.
⁵ Department of Chemical Systems Engineering, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
⁶ School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot 010051, P. R. China.
⁷ Nagoya Industrial Science Research Institute, Nagoya 464-0819, Japan.
⁸ Center of Nanotechnology, King Abdulaziz University, Jeddah 21589, Saudi Arabia.

PMID: 32223205
DOI: 10.1021/acsami.0c01004

Abstract

Mg₃Sb₂-based compounds by virtue of nontoxicity and low-cost have become a promising class of candidates for midtemperature thermoelectric power generation. Here, we successfully fabricated n-type Mg₃Sb₂-based materials using an inexpensive and efficient approach of one-step ball milling and spark plasma sintering, and demonstrate that a complementary and favorable effect of multiple elements coalloying/-doping leads to an excellent thermoelectric performance. The intrinsic p-type conducting behavior for Mg₃Sb₂ could be changed to n-type through Bi and Se coalloying on Sb sublattices with excess Mg, resulting from the suppression of Mg vacancies and the formation of Mg interstitial. Furthermore, Mn doping on Mg sublattices could soften the chemical bonds, leading to the increase of carrier mobility and concentration simultaneously. Additionally, multielement coalloying/-doping could significantly increase the lattice disorder, which undoubtedly strengthens the phonon scattering and readily results in a suppressed lattice thermal conductivity. As a result, a highest ZT value of 1.6 at 723 K and an average ZT value up to 1.1 were obtained in the temperature range of 323-723 K in the Mg_3.18Mn_0.02Sb_1.5Bi_0.49Se_0.01 sample, which is one of the highest values among the Te free Mg₃Sb₂. This work could give guidance for improving the thermoelectric performance of Zintl phase materials or even others using the multielement codoping/-alloying strategy.

Keywords: (Mn, Se) codoping; Zintl compounds; ball milling; n-type Mg3Sb2; spark plasma sintering; thermoelectric materials.