Thermoelectric properties of p-type (Bi,Sb)2Te3 nanocomposites dispersed with multiwall carbon nanotubes

p-type (Bi0.2Sb0.8)2Te3 nanocomposites were prepared by hot-pressing mechanically alloyed (Bi0.2Sb0.8)2Te3 powders with a dispersion of 0–0.25 wt% multiwall carbon nanotubes. The thermal conductivity of the (Bi0.2Sb0.8)2Te3 nanocomposite was substantially reduced from 0.98 W/m × K to 0.71 W/m × K at 75 °C with a dispersion of 0.12 wt% multiwall carbon nanotubes. The dimensionless figure-of-merit of the (Bi0.2Sb0.8)2Te3 nanocomposite was remarkably enhanced from 1.03 to 1.47 at 75 °C by dispersion with 0.12 wt% multiwall carbon nanotubes. An exceptionally high dimensionless figure-of-merit of 1.41 at room temperature was also obtained for the nanocomposite dispersed with 0.12 wt% multiwall carbon nanotubes.