Recent Advances in Thermoelectric Performance of Half-Heusler Compounds

Abstract

Half-Heusler phases (space group F43m, C1b) 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 to 900 degrees 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. Keywords: half-Heusler compounds; figure of merit; power density; lattice disorder; dopant resonant states

10 pages, 6 figures, invited feature paper

References in corpus (1)

• Prediction and accelerated laboratory discovery of previously unknown 18-electron ABX compounds

Cited by in corpus (4)

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• A high throughput search of efficient thermoelectric half-Heusler compounds
• Thermoelectric transport trends in group 4 half-Heusler alloys
• Ab initio study of mechanical and functional properties of novel CaZnC and CaZnSi half-Heusler materials