Synthesis of alumina nanoparticle-embedded-bismuth telluride matrix thermoelectric composite powders

Alumina nanoparticle-embedded-bismuth telluride matrix (Al2O3/Bi2Te3) composite powders were synthesized by chemical routes that employ a polyol reduction process to Bi acetates and Te chlorides in the solvent. With application of the polyol process, the synthesized composite powders show a disc-shaped morphology with 50 nm thickness and 1 mu m diameter. High-resolution TEM images reveal that alumina nanoparticles are homogeneously embedded in the Bi2Te3 matrix powders. The Al2O3/Bi2Te3 nanocomposites sintered from the composite powders exhibit improved ZT values at room temperature compared to that of pure Bi2Te3 due to reduced thermal conductivity caused by active phonon and carrier scattering at the newly formed Al2O3/Bi2Te3 interface. (C) 2012 Elsevier B.V. All rights reserved.