Synthesis and thermoelectric characterization of Bi2Te3 nanoparticles

TL;DR

This paper introduces a new synthesis method for Bi2Te3 nanoparticles, enabling detailed thermoelectric property analysis of sintered pellets with reduced thermal conductivity and preserved electrical properties.

Contribution

It presents a novel synthesis route for near monodisperse Bi2Te3 nanoparticles and demonstrates their thermoelectric properties after sintering, which was not previously reported.

Findings

Reduced thermal conductivity in sintered pellets

Electrical conductivity comparable to bulk Bi2Te3

Successful preservation of crystal grain sizes

Abstract

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.