Growing nanocrystals inside crystals for thermodynamically stable advanced thermoelectrics

PHYS 188

Mercouri G. Kanatzidis, m-kanatzidis@northwestern.edu, Department of Chemistry, Northwestern University and Argonne National Laboratory, 2145 Sheridan Rd, Evanston, IL 60208
There is a strong incentive to develop novel thermoelectric materials for power generation with a vastly improved thermoelectric performance. Nanomaterials have a role to play in meeting this challenge because of expectations for enhanced power factor and greatly reduced thermal conductivity in suitably chosen systems. Therefore general, convenient synthetic routes to bulk nanostructured materials, designed to be thermodynamically stable and thus practically permanent, are needed. First we will define: what is a nanomaterial when it comes to thermoelectric research? We will then present several such concepts in preparing bulk materials containing nanometer-sized coherent and non-coherent inclusions. Coherent embedded nanocrystals in a semiconductor matrix can serve as sites for scattering of acoustic phonons to lower the thermal conductivity. Thus, enhancements in the thermoelectric figure of merit have been demonstrated because of the ability to decouple carrier scattering from phonon scattering mechanisms. This research is teaching us how to design and prepare bulk inexpensive nanostructured thermoelectric materials with high conversion efficiency. Results to this effect will be presented.
 

Nanostructured Materials
8:20 AM-12:00 PM, Tuesday, April 8, 2008 Morial Convention Center -- Rm. 338/339, Oral

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008