Structural variations in indium tin tellurides and their thermoelectric properties

Neudert, Lukas; Schwarzmüller, Stefan; Schmitzer, Silvia; Schnick, Wolfgang and Oeckler, Oliver (2018): Structural variations in indium tin tellurides and their thermoelectric properties. In: Journal of Solid State Chemistry, Vol. 258: pp. 289-297

Abstract

Indium-doped tin tellurides are promising and thoroughly investigated thermoelectric materials. Due to the low solubility of In2Te3 in SnTe and vice versa, samples with the nominal composition (SnTe)(3-3x)(In2Te3)(x) with 0.136 <= x <= 0.75 consist of a defect-rocksalt-type Sn-rich and a defect-sphalerite-type In-rich phase which are endotaxially intergrown and form nanoscale heterostructures. Such nanostructures are kinetically inert and become more pronounced with increasing overall In content. The vacancies often show short-range ordering. These phenomena are investigated by temperature-dependent X-ray diffraction and HRTEM as well as STEM with element mapping by X-ray spectroscopy. The combination of real-structure effects leads to very low lattice thermal conductivity from room temperature up to 500 degrees C. Thermoelectric figures of merit ZT of heterostructured materials with x = 0.136 reach ZT values up to 0.55 at 400 degrees C.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0022-4596
• Language: English