Point defect scattering engineering for effective lattice thermal conductivity reduction in high-entropy-type thermoelectric material with rock salt structure

Recently, high-entropy-type (HE-type) thermoelectric materials have attracted much attention as they show large ZT values caused by low lattice thermal conductivity ( κ lat ) by severe phonon scattering. However, effective κlat reduction is difficult due to the ultra-low κ lat (< 0.5 Wm−1K−1). Here, we found that the mass scattering parameter Γ M of the point defect scattering model shows a negative correlation with the magnitude of κ lat reduction, and AgBi 1− x Sb x TSe 0.8 S 0.6 Te 0.6 for x = 0–0.4 was synthesized to evaluate this strategy. Our findings demonstrate that Γ M values can effectively estimate the magnitude of κ lat reduction, offering a new approach for thermoelectric materials development.