Preparation and thermoelectric properties of Bi2SexTe3−x bulk materials

Bi2Te3 and Bi2Se3 nanoplates were synthesized by a microwave-assisted wet chemical method, and Bi2SexTe3−x (x=1, 2, 3) bulk nanocomposites were then prepared by hot pressing the Bi2Te3 and Bi2Se3 nanoplates at 80 MPa and 723 K in vacuum. The phase composition and microstructures of the bulk samples were characterized by powder X-ray diffraction and field-emission scanning electron microscopy, respectively. The electrical conductivity of the Bi2SexTe3−x bulk nanocomposites increases with increasing Se content, and the Seebeck coefficient value is negative, showing n-type conduction. The absolute Seebeck coefficient value decreases with increasing Se content. A highest power factor, 24.5 µWcm−1 K−2, is achieved from the sample of x=1 at 369 K among the studied samples.