High Thermoelectric Figure of Merit of Ag₈SnS₆ Component Prepared by Electrodeposition Technique

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.