J. Mater. Sci. Technol. ›› 2022, Vol. 114: 55-61.DOI: 10.1016/j.jmst.2021.12.002

• Research Article • Previous Articles     Next Articles

High thermoelectric and mechanical performance in the n-type polycrystalline SnSe incorporated with multi-walled carbon nanotubes

Xin-Yu Maoa, Xiao-Lei Shib,c, Liang-Chuang Zhaia, Wei-Di Liud, Yue-Xing Chene, HanGao f, Meng Lig, De-Zhuang Wanga, Hao Wua, Zhuang-Hao Zhenge, Yi-Feng Wangh,i, Qingfeng Liua,j,*(), Zhi-Gang Chenb,c,*()   

  1. aState Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
    bCentre for Future Materials, University of Southern Queensland, Springfield Central, Brisbane, 4300, Australia
    cSchool of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4000, Australia
    dAustralian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
    eShenzhen Key Laboratory of Advanced Thin Films and Applications, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
    fKey Laboratory of Material Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450052, China
    gSchool of Mechanical and Mining Engineering, The University of Queensland, St Lucia, Brisbane, QLD 4072, Australia
    hCollege of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China
    iJiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites, Nanjing Tech University, Nanjing 211816, China
    jCAS Key Laboratory of Carbon Materials, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, China
  • Received:2021-10-27 Revised:2021-11-29 Accepted:2021-12-08 Published:2022-07-01 Online:2022-01-13
  • Contact: Qingfeng Liu,Zhi-Gang Chen
  • About author:zhigang.chen@qut.edu.au, zhigang.chen@uq.edu.au (Z.-G. Chen).
    *E-mail addresses: qfliu@njtech.edu.cn (Q. Liu),
    First author contact:

    1These authors contribute equally to this work.

Abstract:

In this study, we introduce multi-walled carbon nanotubes (MWCNTs) in Pb/I co-doped n-type polycrystal SnSe to simultaneously improve its thermoelectric and mechanical properties for the first time. The introduced MWCNTs act as the “bridges” to accelerate the electron carrier transport between SnSe grains, leading to significantly increased electrical conductivity from 32.6 to 45.7 S cm-1 at 773 K, which contributes to an enhanced power factor of ∼5.0 μW cm-1 K - 2 at this temperature. Although MWCNTs possess high intrinsic thermal conductivities, these MWCNTs, acting as nanoinclusions in the SnSe matrix to form the dense interfaces between SnSe and MWCNTs, provide extra heat-carrying phonon scattering centers, leading to a slightly reduced lattice thermal conductivity of only 0.34 W m - 1 K - 2 at 773 K and in turn, a high ZT of ∼1.0 at this temperature. Furthermore, the introduced MWCNTs can simultaneously act as the “binders” to bond adjacent grains, significantly improving the mechanical properties of SnSe by boosting its Vickers hardness from 39.5 to 50.5. This work indicates that our facile approach can achieve high thermoelectric and mechanical properties in n-type SnSe polycrystals with a considerable potential for applying to thermoelectric devices as n-type elements.

Key words: Thermoelectric property, SnSe, N-type, Multi-walled carbon nanotubes, Mechanical property