High Temperature Transport Properties of Tetrahedrite Cu12-xMxSb4-yTeyS13 (M = Zn, Ni) Compounds

Natural and synthetic tetrahedrites are currently the focus of attention in thermoelectricity due to their abundance, numerous possibilities of substitution, and their complex crystal structure (I (4) over bar 3m) resulting in extremely low lattice thermal conductivity (below 1 W m(-1) K-1 above 300 K). Here, we report on the synthesis, structural and chemical characterizations, and high-temperature thermoelectric properties of polycrystalline Cu12-xMxSb4-yTey S-13 (M = Zn, Ni) tetrahedrites. Upon substituting on both the Cu and Sb sites, we successfully improved the thermoelectric properties with respect to the ternary compound Cu12Sb4S13 with peak ZT values of 0.7 at 700 K.