Abstract
The role of electron-phonon (EP) scattering in lattice thermal conductivity (κL) of thermoelectric material has not been fully studied until now, especially for the decisive factors that influence the reduction of κL. To address this issue, we report the effect of EP interactions on κL at a series of temperatures and carrier concentrations for 18 half-Heusler compounds. Among all the compounds investigated, the hole-doped TiCoSb and the electron-doped ZrIrSb have the largest κL reductions (32% & 20%) by EP interactions at 300 K, under the carrier concentration of 1021 cm−3. Detailed analyses reveal that the system with strong EP coupling strength and high electronic density of states at the Fermi level (N (EF)) favor the κL reduction, because these two factors are beneficial for EP scattering rates. And a high N (EF) can be caused by a high carrier concentration and/or a large effective mass. Temperature is another factor that affects the reduction of κL by EP interactions due to its imbalance influence on EP and phonon-phonon (PP) scatterings. Furthermore, after considering the influences from the aliovalent doping and grain boundary, the EP interactions still play a non-negligible role on κL reduction, especially at low temperatures and high carrier concentrations. Our work provides a complete picture for understanding the mechanism of EP interactions in material's thermal transport.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
