Discovery of ZrCoBi based half Heuslers with high thermoelectric conversion efficiency.

ABSTRACT: Thermoelectric materials are capable of converting waste heat into electricity. The dimensionless figure-of-merit (ZT), as the critical measure for the material's thermoelectric performance, plays a decisive role in the energy conversion efficiency. Half-Heusler materials, as one of the most promising candidates for thermoelectric power generation, have relatively low ZTs compared to other material systems. Here we report the discovery of p-type ZrCoBi-based half-Heuslers with a record-high ZT of ?1.42 at 973?K and a high thermoelectric conversion efficiency of ?9% at the temperature difference of ?500?K. Such an outstanding thermoelectric performance originates from its unique band structure offering a high band degeneracy (N_v) of 10 in conjunction with a low thermal conductivity benefiting from the low mean sound velocity (v_m ?2800?m?s^-1). Our work demonstrates that ZrCoBi-based half-Heuslers are promising candidates for high-temperature thermoelectric power generation.

SUBMITTER: Zhu H 

PROVIDER: S-EPMC6021448 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature