A thermoelectric nanocomposite of Bi${}_{0.5}$Sb${}_{1.5}$Te${}_3$ with the C${}_{60}$ fullerene molecules has been synthesized and studied. The fullerene molecules provide the phonons blocking, reducing the lattice thermal conductivity. The reduction of the electrical conductivity is much less than the heat conductivity reduction at a low fullerene content. Therefore, the thermoelectric figure of merit increases up to 25$\%$ at 305 K. The thermoelectric properties of the synthesized materials have been analyzed theoretically in the frame of the Boltzmann equation approach. The calculations predict the optimal carrier concentration and C${}_{60}$ content for a maximal value of the thermoelectric figure of merit in a wide temperature range.

• Received 27 March 2012

DOI:https://doi.org/10.1103/PhysRevB.86.075426