Vacancy phonon scattering in thermoelectric In2Te3–InSb solid solutions

Solid solution formation is a common and effective approach to reduce the lattice thermal conductivity for thermoelectric materials because of additional phonon scattering by point defects due to mass and strain fluctuations. This scattering is maximal for vacancies. In this paper we present an example of the strong effect of phonon-vacancy scattering for the InSb–In2Te3 system. The measured transport properties show a reduction by more than an order of magnitude of the lattice thermal conductivity. Further efforts are also made on optimization for thermoelectric applications through doping. Our results indicate that these solid solutions are a prospective new-type thermoelectric material.