InTe (Indium Telluride)

A layered III–VI chalcogenide with a quasi-one-dimensional TlSe-type structure, space group I4/mcm, containing mixed-valence In⁺ and In³⁺ sites. It is a narrow-bandgap semiconductor notable for its exceptionally low lattice thermal conductivity, arising from the anharmonic rattling of the weakly bound In⁺ cations, which makes it a promising thermoelectric material. Its chain-like structure and lone-pair-driven phonon scattering establish InTe as an important platform for studying phonon anharmonicity and low-thermal-conductivity thermoelectrics.