TEM Analyses of Bismuth-Antimony Thermoelectric Nanowires

Thermoelectric materials have diverse applications for solid-state cooling and power generation, but at present have poor energy conversion efficiencies. Theory has long predicted that Bi-based nanowires could achieve dramatic improvements in thermoelectric performance through quantum confinement to create peaks in the electronic density-of-states that enhance the thermoelectric power factor [1,2]. However, achieving this promise has been difficult, in part because of the experimental challenges of controlling the materials growth in these systems. Key issues include control of composition and crystallinity. In this presentation, we will discuss our electron microscopic investigation of nanowires based on alloys of Bi and Sb, with the goal of understanding the underlying compositional and microstructural issues necessary for improving nanowire growth and quality.