Improved thermoelectric figure of merit in n-type CoSb3 based nanocomposites

Nanocomposites offer a promising approach to incorporate nanostructured constituents to bulk thermoelectric materials. n-type CoSb3 nanocomposites were prepared by hot pressing the mixture of nanoscale and microsized CoSb3 powders synthesized by solvothermal method and melting, respectively. Microstructure analysis shows that the bulk materials are composed of nano- and micrograins. The nanocomposite structures are effective in reducing thermal conductivity more than electrical conductivity, hence in improving the thermoelectric performance. A dimensionless figure of merit of 0.71 is obtained for the nanocomposite with 40wt% nanopowder inclusions, about 54% increase of that without nanopowder inclusions.