Advanced Energy Materials, Год журнала: 2025, Номер unknown

Опубликована: Апрель 25, 2025

Abstract State‐of‐the‐art thermoelectric materials typically exhibit high charge carrier mobility. However, this study reveals an exception in MnGeTe 2 alloys, where the room‐temperature hole mobility is intrinsically low, approaching Ioffe–Regel limit. Through heavy alloying with AgSbTe , electronic band structure of transitions from a single valence to multiple bands, driven by enhanced spin‐orbit coupling due incorporation heavier Ag and Sb elements. This restructuring increases density states effective mass 50%, 10 m e 15 significantly enhancing Seebeck coefficient despite higher concentrations. Remarkably, remains unchanged, as mean free path carriers has already reached its minimum. Additionally, induces lattice softening confirmed sound velocity measurements. softening, combined effect, reduces thermal conductivity amorphous Further optimization Ag/Sb ratio enables precise tuning density, resulting exceptional peak ZT value 1.7 at 868 K for Mn 0.7 Ge 0.2 0.4 Te sample — 60% improvement over pristine . work demonstrates promise low‐mobility systems near limit high‐performance thermoelectrics, revealing synergistic electronic–lattice interactions.

Язык: Английский