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 1.46x10(17) 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 3.8Wm(-1)K(-1), high electrical conductivity of 2.4 x 10(5) Sm-1, Seebeck coefficient of -180 mu VK-1 and a power factor of 6.9mWK(-2)m(-1), implying that it is more efficient than those obtained in recently experimental investigations for thermoelectric devices.