Thermoelectric characteristics of the (Bi,Sb)2(Te,Se)3 nanocomposites processed with nanoparticle dispersion

The p-type (Bi0.2Sb0.8)2Te3 and the n-type Bi2(Te0.9Se0.1)3 thermoelectric nanocomposites were processed with dispersion of multi-walled carbon nanotubes and Al2O3 nanopowders. The lattice thermal conductivity κph of the p-type (Bi,Sb)2Te3 was effectively reduced from 0.64 W/m K to 0.45–0.54 W/m K by dispersion of carbon nanotubes. The room-temperature figure-of-merit of the p-type (Bi,Sb)2Te3 was improved from 3.37 × 10−4/K to 3.52 × 10−4/K with dispersion of 0.05 vol.% carbon nanotubes. The figure-of-merit of the n-type Bi2(Te,Se)3 at 75 °C was substantially improved from 2.9 × 10−4/K to 3.5 × 10−4/K with dispersion of 0.5 vol.% Al2O3 nanopowders.