Thermoelectric properties of Co substituted synthetic tetrahedrite

Tetrahedrite compounds Cu12−xCoxSb4S13 (0 ⩽ x ⩽ 2.0) were prepared by solid state synthesis. XPS revealed that Co partially substitutes Cu1+ as well as Cu2+. A systematic trend in the increase of resistivity and Seebeck coefficient with rising of doping content was observed. Also, a systematic decrease of total thermal conductivity with doping was found. As a combined effect of power factor and total thermal conductivity, the maximum thermoelectric figure of merit (zT) 0.98 was obtained at 673 K for Cu11.5Co0.5Sb4S13.105