Abstract Scope |
GeTe-based alloys, which exhibit a vast amount of Ge vacancies, are promising mid-temperature thermoelectric (TE) materials with excellent electrical conductivity. Contradictorily, the high thermal conductivity limits the thermal-to-electrical conversion efficiency in rhombohedral GeTe. Microstructure engineering coupled with doping suppress the thermal conductivity while retain the intrinsically high electrical conduction. Examples can be given in In-GeTe alloys which show 200% reduction in thermal conductivity compared with undoped GeTe. Meanwhile, the Seebeck coefficient of In-GeTe gradually increases, leading to an outstanding power factor in rhombohedral phase region. In short, the In-GeTe shows superior TE performance due to the synergistic approaches of microstructural and doping engineering. |