Enhanced thermoelectric figure of merit of p-type Si0.8Ge0.2 nanostructured spark plasma sintered alloys with embedded SiO2 nanoinclusions

We report on thermoelectric properties of p-type boron doped nanostructured bulk Si80Ge20 synthesized via spark plasma technique. We demonstrate that the presence of a limited amount of nanometer-sized SiO2 inclusions, resulting from the oxidation during processing stages is an effective way to further thermal conductivity reduction in the nanostructured Si80Ge20 alloys. Significant reduction of thermal conductivity and high values of Seebeck coefficient allowed us to reach a peak ZT value of about 0.72 at 800 degrees C in boron doped Si80Ge20. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.