Vacancy‐Filling Heusler Thermoelectric Compounds

Abstract 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.