Synthesis, Fabrication, and Characterization of Multidimensional Nanoparticle Based Thermoelectric Materials Composed of Bismuth, Antimony, and Tellurium.

Abstract

With the event 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 devised a synthetic technique towards nanoparticles composed of bismuth, antimony, and tellurium that has proven highly versatile in tuning both the composition and shape/structure of the resulting nanoparticles. The ability to control the nanoparticle composition and shape/structure are highly important as these are critical parameters that dictate the resulting devices TE activity. In a modified polyol synthetic technique, it was found that many complex composition, shape, and structure combinations could be obtained for the nanoparticles including Bi-Sb nanodiscs with controllable size, a heterostructure composed of Sb₂Te₃ nanodiscs deposited on Te nanowires, or small particles deposited on a (Bi_0.5Sb_0.5)₂Te₃ wire, just to name a few. By simply changing the capping ligands used in the synthesis, the nanoparticles resulting composition, morphology and structure could be changed, leading to a straightforward route towards TE nanoparticles with interesting properties. This presentation focuses on our recent study of the synthesis of bismuth, antimony, and tellurium composite nanoparticles with applications in thermoelectric materials in terms of understanding the underlying mechanisms of the synthetic technique, and characterization of the resulting nanomaterial properties.