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

摘要

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 microscopy (SEM) analysis. A special emphasis was paid to the effects of chemical composition, especially the Pb content on the thermoelectric properties of the Ag_(0.8)Pb_(18+x)SbTe_(20) samples, including electrical resistivity, Seebeck coefficient, power factor, thermal conductivity and dimensionless figure of merit. The present study reveals that the optimal composition of Ag_(0.8)Pb_(18+x)SbTe_(20) samples is Ag_(0.8)Pb_(22.5)SbTe_(20) and the maximum figure of merit (ZT) is 1.2 at 673 K.