ICT2014 Abstracts

This presentation will discuss progress and challenges in thermoelectric transport, materials, characterization, and systems, building on research conducted at the DOE Solid-State Solar Thermal Energy Conversion Center (S3TEC), and other research programs at MIT.  Nanostructured materials, such as nanocomposites, have been shown experimentally as an effective approach to increase the figure of merit of a wide range of materials.  Understanding and predicting phonon and electron transport in such structures, however, have proven to be challenging due to multiple length scales and complicated materials structures involved.  Good progress has been made in predicting phonon transport in single crystals and at interfaces based on first-principles, leading to detailed information on phonon spectra and mean free path that can be compared with data extracted from inelastic neutron scattering experiments.  Desktop optical experiments have been developed to explore ballistic phonon transport to map out phonon contributions to thermal conductivity.  These advances can be used to gain new insights on promising thermoelectric materials and engineering nanostructures to improve ZT.   For electron transport, scattering calculation is now also possible with density-functional theory, in addition to the constant relaxation approximation approach.  New ideas to engineering electron scattering such as modulation doping and cloaking will be discussed.  With the increased ZT values on different materials, it is extremely important to develop characterization tools for data validation and to identify new applications.  Our recent progress in property characterization in device configurations, and device prototyping in solar-thermoelectric generators will be discussed.  Challenges for future advances will be discussed along the way.  This work was partially funded by ‘Solid State Solar-Thermal Energy Conversion Center (S³TEC)’, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number: DE-SC0001299/DE-FG02-09ER46577, by DOE EERE under Award number: DE-EE0005806, and by AFOSR MURI via Ohio State University.