Jessica L. Lensch-Falk

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.

Compositional Ordering and Stability in Nanostructured, Bulk Thermoelectric Alloys

Thermoelectric materials have many applications in the conversion of thermal energy to electrical power and in solid-state cooling. One route to improving thermoelectric energy conversion efficiency in bulk material is to embed nanoscale inclusions. This report summarize key results from a recently completed LDRD project exploring the science underpinning the formation and stability of nanostructures in bulk thermoelectric and the quantitative relationships between such structures and thermoelectric properties.