Thermoelectric properties of n-type Bi2Te2.7Se0.3 compounds prepared by spark plasma sintering

In this study, the thermoelectric properties of 0.1 wt.% Cdl(2)-doped n-type Bi2Te2.7Sb0.3 compounds, fabricated by SPS in a temperature range of 250 degrees C to 350 degrees C, were characterized. The density of the compounds was increased to approximately 100 % of the theoretical density by carrying out consolidation at 350 degrees C. The Seebeck coefficient, thermal conductivity, and electrical resistivity were dependent on a hydrogen reduction process and the sintering temperature. The Seebeck coefficient and the electrical resistivity increased with the reduction process. Also, electrical resistivity decreased and thermal conductivity increased with sintering temperature. The results suggest that carrier density and mobility vary according to the reduction process and sintering temperature. The highest figure of merit, 1.93 x 10(-3) K-1, was obtained for the compound consolidated at 350 degrees C for 2 min.