Vacancy-Filling Heusler Thermoelectric Compounds

Heusler compounds, particularly half-Heuslers, have been emerging as promising thermoelectric materials due to their high performance and mechanical robustness. This perspective summarizes the vacancy-filling strategy as a novel approach to enhance thermoelectric performance in thermoelectric Heusler compounds. By partially occupying the 4d Wyckoff sites, this strategy modifies crystal symmetry, tailors band structures, and introduces mass/strain fluctuations, significantly reducing lattice thermal conductivity. The perspective highlights how vacancy-filling bridges half-Heusler and full-Heusler phases, enabling high thermoelectric performance while uncovering exotic physical phenomena.