Preparation of p- and n-type SiC-based thermoelectric materials by spark plasma sintering

We report on the preparation of Si₃N₄ or Al₄C₃ added SiC by spark plasma sintering (SPS) and their thermoelectric properties. The relative densities of all the sintered materials were more than 80% of the theoretical value. The conduction types were controlled by the addition of Si₃N₄ for n-type and Al₄C₃ for p-type. The electrical resistivity decreased and the Seebeck coefficient increased with temperature. We also found that the power factor depends on the composition of the Si₃N₄ or Al₄C₃ and takes the maximum value at 7wt% addition at 973K.