Structural effects on the lattice thermal conductivity of ternary antimony- and bismuth-containing chalcogenide semiconductors

The lattice thermal conductivities Cu3SbSe4 and Cu3SbSe3 have been measured. While the former compound exhibits classical behavior, the lattice thermal conductivity of Cu3SbSe3 is anomalously low. We speculate that, similar to the case of AgSbTe2, the low thermal conductivity in Cu3SbSe3 has its origin in strong anharmonicity induced by the presence of the two additional nonbonding electrons in the valence shell of the Sb3+ ions. Anomalously low thermal conductivity is also demonstrated in compounds in which Bi occurs in the trivalent state. The results have implications in the design of thermoelectric semiconductors with intrinsically low thermal conductivity.