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SJTU Researchers Advanced Carrier Scattering Phase Diagram for Thermoelectric Materials

June 22, 2020      Author: Ma Jie

On June 19, 2020, Special Researcher Ma Jie from School of Physics and Astronomy, SJTU and Dr. Ren Qingyong, together with Dr. Fu Chenguang from Max Planck Institute, SJTU Prof. Yang Jiong, Prof. Zhu Tiejun from Zhejiang University and other researchers, published their latest findings on Nature Communications under the title "Establishing the carrier scattering phase diagram for ZrNiSn-based half-Heusler thermoelectric materials". The paper reveals the influence of carrier concentration on thermoelectric effect and sheds lights on the optimization of the thermoelectric performance. Dr. Ren Qingyong is the first author; Ma Jie is the corresponding author; Dr. Fu Chenguang and Prof. Yang Jiong are the co-corresponding authors.

Their research has been sponsored by National Natural Science Foundation of China, Project 111,Alexander von Humboldt Foundation, Japanese Spallation Neutron Source and China Spallation Neutron Source.

Abstract

Chemical doping is one of the most important strategies for tuning electrical properties of semiconductors, particularly thermoelectric materials. Generally, the main role of chemical doping lies in optimizing the carrier concentration, but there can potentially be other important effects. Here, we show that chemical doping plays multiple roles for both electron and phonon transport properties in half-Heusler thermoelectric materials. With ZrNiSn-based half-Heusler materials as an example, we use high-quality single and polycrystalline crystals, various probes, including electrical transport measurements, inelastic neutron scattering measurement, and first-principles calculations, to investigate the underlying electron-phonon interaction. We find that chemical doping brings strong screening effects to ionized impurities, grain boundary, and polar optical phonon scattering, but has negligible influence on lattice thermal conductivity. Furthermore, it is possible to establish a carrier scattering phase diagram, which can be used to select reasonable strategies for optimization of the thermoelectric performance.

 

 Link: https://www.nature.com/articles/s41467-020-16913-2

 

Translated  by Zhang Wenying     Reviewed by Wang Bingyu