Thermoelectric properties of Cu₁₂(Zn)Sb₄(Bi)S₁₃ tetrahedrites

In the present work, Zn and Bi co-doping of Cu₁₂Sb₄S₁₃-based tetrahedrites have been carried out at the Cu and Sb site, respectively. This dual-site doping was performed to optimize the balance between the electrical and thermal transport properties, thereby improving thermoelectric  efficiency. Sb and Bi substituted tetrahedrite materials Cu_12-xZn_xSb_0.95Bi_0.05S₁₃ (x=0.1-0.2) were prepared by means of solid-state reaction using cold pressing. The polycrystalline material was crashed into small powder and pressed to obtain square pellets 1 cm² for easier transport measurments. Seebeck coefficients up to 160 μV/K and figure of merits up to 2 have been obtained.