Beneficial Contribution of Alloy Disorder to Electron and Phonon Transport in Half-Heusler Thermoelectric Materials

Authors

  • Hanhui Xie,

    1. State Key Laboratory of Silicon Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
    Search for more papers by this author
  • Heng Wang,

    1. Department of Materials Science, California Institute of Technology, Pasadena, CA 91125, USA
    Search for more papers by this author
  • Yanzhong Pei,

    1. Department of Materials Science, California Institute of Technology, Pasadena, CA 91125, USA
    Current affiliation:
    1. School of Materials Science and Engineering, Tongji University, 4800 Caoan Road, Shanghai 201804, China
    Search for more papers by this author
  • Chenguang Fu,

    1. State Key Laboratory of Silicon Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
    Search for more papers by this author
  • Xiaohua Liu,

    1. State Key Laboratory of Silicon Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
    Search for more papers by this author
  • G. Jeffrey Snyder,

    1. Department of Materials Science, California Institute of Technology, Pasadena, CA 91125, USA
    Search for more papers by this author
  • Xinbing Zhao,

    1. State Key Laboratory of Silicon Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
    Search for more papers by this author
  • Tiejun Zhu

    Corresponding author
    1. State Key Laboratory of Silicon Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, China
    • State Key Laboratory of Silicon Materials, Department of Material Science and Engineering, Zhejiang University, Hangzhou 310027, China, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province, Zhejiang University, Hangzhou 310027, China.

    Search for more papers by this author

Abstract

Electron and phonon transport characteristics determines the potential of thermoelectric materials for power generation or refrigeration. This work shows that, different from most of high performance thermoelectric materials with dominant acoustic phonon scattering, the promising ZrNiSn based half-Heusler thermoelectric solid solutions exhibit an alloy scattering dominated charge transport. A low deformation potential and a low alloy scattering potential are found for the solid solutions, which is beneficial to maintain a relatively high electron mobility despite of the large effective mass, and can be intrinsic favorable features contributing to the noticeably high power factors of ZrNiSn based alloys. A quantitive description of the different phonon scattering mechanisms suggests that the point defect scattering is the most important mechanism that determines the phonon transport process of the solid solutions. The present results indicate that alloying can be an effective approach for such materials systems to enhance thermoelectric figure of merit ZT by reducing phonon thermal conductivity, while minimizing the deterioration of charge mobility due to the low alloy scatteirng potential.

Ancillary