High Thermoelectric Figure of Merit of Ag8SnS6 Component Prepared by Electrodeposition Technique**Supported by the Scientific Research Deanship of University of Dammam under Grant No 2014264.

Abstract

A new thermoelectric material Ag8SnS6, with ultra-low thermal conductivity in thin film shape, is prepared on indium tin oxide coated glass (ITO) substrates using a chemical process via the electrodeposition technique. The structural, thermal and electrical properties are studied and presented in detail, which demonstrate that the material is of semiconductor type, orthorhombic structure, with a band gap in the order of 1.56 eV and a free carrier concentration of 1.46 × 1017 cm−3. The thermal conductivity, thermal diffusivity, thermal conduction mode, Seebeck coefficient and electrical conductivity are determined using the photo-thermal deflection technique combined with the Boltzmann transport theory and Cahill's model, showing that the Ag8SnS6 material has a low thermal conductivity of 3.8 Wm−1K−1, high electrical conductivity of 2.4 × 105 Sm−1, Seebeck coefficient of − 180 μVK−1 and a power factor of 6.9 mWK−2m−1, implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.