Fabrication and property of high-performance Ag-Pb-Sb-Te system semiconducting thermoelectric materials

High performance Ag-Pb-Sb-Te system thermoelectric bulk materials were fabricated by a combination of mechanical alloying (MA) and spark plasma sintering (SPS). Phase composition and microstructure of the resultant materials were investigated by X-ray diffraction (XRD) and scanning electron micros-copy (SEM) analysis. A special emphasis was paid to the effects of chemical composition, especially the Pb content on the thermoelectric properties of the Ag0.8Pb18 xSbTe20 samples, including electrical resistivity, Seebeck coefficient, power factor, thermal conductivity and dimensionless figure of merit. The present study reveals that the optimal composition of Ag0.8Pb18 xSbTe20 samples is Ag0.8Pb22.5SbTe20 and the maximum figure of merit (ZT) is 1.2 at 673 K.