PbTe-based thermoelectric nanocomposites with reduced thermal conductivity by SiC nanodispersion

For further thermoelectric performance enhancement by the nanocomposite effect, a small amount (<2 vol. %) of 30 nm SiC particles were added into a compositionally optimized AgPbmSbTem+2 thermoelectric alloy fabricated by mechanical alloying and spark plasma sintering. Although the energy filtering effect is not available in the present composite due to the mismatched interface between SiC and the matrix, a small amount of SiC dispersions were revealed to be effective to reduce the thermal conductivity via enhancing phonon scattering. A high figure of merit up to 1.54 at 723 K was obtained in the AgPbmSbTem+2 matrix composite containing 1 vol. % SiC nanoparticles.