Recent Advances in Thermoelectric Performance of Half-Heusler Compounds

Metals

S.Joseph Poon¹ 

[1] Department of Physics, University of Virginia, Charlottesville, VA 22904-4714, USA;

关键词: half-Heusler compounds;    figure of merit;    power density;    lattice disorder;    dopant resonant states;   

DOI  :  10.3390/met8120989

来源: DOAJ

【 摘 要 】

Half-Heusler phases (space group $\mathrm{F}\overline{4}3\mathrm{m}$ , C1_b) have recently captured much attention as promising thermoelectric materials for heat-to-electric power conversion in the mid-to-high temperature range. The most studied ones are the RNiSn-type half-Heusler compounds, where R represents refractory metals Hf, Zr, and Ti. These compounds have shown a high-power factor and high-power density, as well as good material stability and scalability. Due to their high thermal conductivity, however, the dimensionless figure of merit (zT) of these materials has stagnated near 1 for a long time. Since 2013, the verifiable zT of half-Heusler compounds has risen from 1 to near 1.5 for both n- and p-type compounds in the temperature range of 500⁻900 °C. In this brief review, we summarize recent advances as well as approaches in achieving the high zT reported. In particular, we discuss the less-exploited strain-relief effect and dopant resonant state effect studied by the author and his collaborators in more detail. Finally, we point out directions for further development.

【 授权许可】

Unknown