Thermoelectric properties of CuyBixSb2−x−yTe3 alloys fabricated by mechanical alloying and spark plasma sintering

In this work, CuyBixSb2−x−yTe3 alloys containing a small amount (0.1 vol%) of SiC nano-particles were prepared by spark plasma sintering using mechanical alloying derived powders. It is found that both the electrical resistivity and Seebeck coefficient of (Bi,Sb)2Te3 alloy are significantly decreased by doping a trace Cu and increasing Sb-to-Bi ratio, but the thermal conductivity of (Bi,Sb)2Te3 alloy is also obviously increased by doping a trace Cu, especially at low temperature. A peak ZT value about 1.23 is obtained at 423 K for Bi0.3Sb1.7Te3, in which all ZT values at the whole measuring temperature range are above 1.0. Such ZT characteristics are more attractive for commercial applications.