Synthesis and thermoelectric characterization of Bi2Te3 nanoparticles

We report a novel synthesis for near monodisperse, sub-10-nm Bi2Te3 nanoparticles. At first, a new reduction route to bismuth nanoparticles is described which are applied as starting materials in the formation of rhombohedral Bi2Te3 nanoparticles. After ligand removal by a novel hydrazine hydrate etching procedure, the nanoparticle powder is spark plasma sintered to a pellet with preserved crystal grain sizes. Unlike previous works on the properties of Bi2Te3 nanoparticles, the full thermoelectric characterization of such sintered pellets shows a highly reduced thermal conductivity and the same electric conductivity as bulk n-type Bi2Te3.