Effect of nano-SiC dispersion on thermoelectric properties of Bi2Te3 polycrystals

Nano-SiC dispersed Bi2Te3 was synthesized by mechanical alloying (MA) followed by spark plasma sintering (SPS). The effects of SiC dispersion on the thermoelectric properties of the SPS-sintered Bi2Te3 alloys were investigated. The results revealed that SiC dispersion in the Bi2Te3 matrix increased the absolute value of Seebeck coefficient. Although the electrical resistance was increased somewhat, Bi2Te3 with 0.1 wt% SiC showed a higher power factor than Bi2Te3 without SiC. Because the dispersion of SiC nano-particles reduced the thermal conductivity at the same time, 0.1 wt% (∝0.24 vol% SiC) addition of SiC nano-particles increased the figure of merit of Bi2Te3 by 18%. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)