Topological states of thermoelectric Yb-filled skutterudites

The effects of topological states on the thermoelectric performance of a highly efficient thermoelectric Yb-filled CoSb3 skutterudite are investigated through combined ab initio calculations and electrical transport measurements. The nontrivial topological states are revealed by ab initio calculations and inferred from anoma-lous Hall conductivity and magnetoresistance. The linear bands associated with the topological states lead to low single-band effective mass and high carrier mobility, and consequently high power factor. Furthermore, the additional band minima due to filling the voids with Yb atoms raise the valley degeneracy, which favors the density-of-states effective mass and thus the Seebeck coefficient but scarcely changing the carrier mobility. These effects together contribute to the high power factor of Yb-filled CoSb3 skutterudite. Our results show that topological states play a crucial role in improving the performance of thermoelectric materials.

Automated summary

The effects of topological states on the thermoelectric performance of a Yb-filled CoSb3 skutterudite are studied. The nontrivial topological states are revealed by ab initio calculations and inferred from anomalous Hall conductivity and magnetoresistance. The linear bands associated with the topological states result in low effective mass and high carrier mobility, leading to high power factor. Additionally, filling the voids with Yb atoms raises the valley degeneracy, favoring the Seebeck coefficient and density-of-states effective mass. These effects contribute to the high power factor of the Yb-filled CoSb3 skutterudite. Our results highlight the crucial role of topological states in improving the performance of thermoelectric materials.