Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published November 6, 2013 | public
Journal Article

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

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 scattering potential.

Additional Information

© 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. Received: February 21, 2013; Revised: March 18, 2013; Published online: April 30, 2013. The authors would like to thank Prof. Jihui Yang from the University of Washington, Seattle for the valuable discussions. This work is supported by the National Basic Research Program of China (Grant No. 2013CB632503), the Nature Science Foundation of China (Grant Nos. 51171171 and 51271165), and the Program for New Century Excellent Talents in University (NCET-12-0495). Y.P. acknowledges the National Junior 1000 Plan and Shanghai Eastern Scholar program for funding supports.

Additional details

Created:
August 22, 2023
Modified:
October 25, 2023