Temperature and porosity dependence of the thermoelectric properties of SiC/Ag sintered materials

We have studied the thermoelectric properties of a SiC-based thermoelectric semiconductor with Ag and polysilastylene (PSS) as a dopant and as a sinte ring additive, respectively. AE is an effective dopant to decrease the elec trical resistivity of the SiC-based p-type thermoelectric semiconductor. It introduces carrier (hole) concentration 10(3)-10(4) times larger than the case of Al-doped SiC with the typical doping concentration. PSS can control the sample density, which is one of the important factors in decreasing th e electrical resistivity and thermal conductivity of the sintered samples. The figure of merit of the sample with Ag 2.0 wt% and PSS 0.1 wt% was estim ated to reach 4 x 10(-4) K-1 at 700 degrees C. This value implies that the SiC/Ag system is one of the promising thermoelectric materials for a high-t emperature region.