Design and Synthesis of One and Two Dimensional Thermoelectric Nanomaterials Composed of Bismuth, Antimony, and Tellurium

Abstract

With the advent of nanotechnology, the field of thermoelectric (TE) materials has been re-invigorated with many recent advances towards materials with high thermoelectric efficiency (dimensionless figure of merit, ZT). The realization of such materials opens up new avenues to the creation of devices that can be used in freon-less refrigeration, micro-electronic cooling, or for harnessing lost heat energy from sources such as car engines. In our own research work, we have successfully synthesized thermoelectric nanoscale materials composed of bismuth, antimony, and tellurium. By using a wet chemical thermal reduction procedure, we were able to create bismuth, antimony, and tellurium composite particles. What's more, by employing different molecular encapsulating agents in the synthesis, we were able to control the resulting shapes of the nanomaterials, resulting in both one and two dimensional bismuth, antimony, and tellurium nanoparticles. The one dimensional nanowires exhibit a micron scale length and ∼20-50nm diameter, while the two dimensional nanodiscs exhibit a diameter of ∼100nm and a thickness of ∼25nm. The unique morphology of these materials make them ideal candidates for processing into functional thermoelectric devices. This paper focuses on our recent study of the synthesis of bismuth, antimony, and tellurium composite nanomaterials of a nanowire and nanodisc morphology, which was directed by the capping agents used in the synthesis. Part of our preliminary study includes analysis of the thermoelectric efficiency of the materials. The resulting nanomaterials are characterized using techniques such as HR-TEM, XPS, XRD, and SEM the results of which provide insight into the design and synthesis of nanoscale materials with enhanced thermoelectric properties.