Facile chemical synthesis of nanocrystalline thermoelectric alloys based on Bi−Sb−Te−Se

Abstract

High yield syntheses of size-confined Bi₂Te₃ and Sb₂Te₃ nanocrystals and nanoflakes, and their alloys, were carried out by a facile glycol-mediated solvothermal process. Phase purity and good crystalline quality were achieved for all alloy compositions by this synthesis process. The isotropically and anisotropically shaped nanocrystals were obtained without using any capping molecule, template, or ligand. Plausible growth mechanisms have been proposed. Densification via spark plasma sintering allowed for dense bulk polycrystalline specimens with nonagglomerated nanograins. This work is of interest in the context of research toward enhancing the thermoelectric properties of these materials. The synthesis process may be modified and extended to design nanostructures of thermoelectric materials with related crystal structures.