APS March Meeting 2012
Volume 57, Number 1
Monday–Friday, February 27–March 2 2012;
Boston, Massachusetts
Session A17: Focus Session: Thermoelectrics - Nanostructured and Oxide TE
8:00 AM–11:00 AM,
Monday, February 27, 2012
Room: 252A
Sponsoring
Units:
DMP GERA FIAP
Chair: Li Shi, University of Texas at Austin
Abstract ID: BAPS.2012.MAR.A17.4
Abstract: A17.00004 : Nanostructured Thermoelectrics and the New Paradigm*
8:36 AM–9:12 AM
Preview Abstract
View Presentation
Abstract
Author:
Mercouri Kanatzidis
(Northwestern University)
A comprehensive and stable energy strategy would require proportionate
attention to all three legs of the ``energy stool''; supply (sources),
demand (efficiency) and storage/transport (delivery). Thermoelectric
materials, that convert waste thermal energy into useful electrical energy,
have an important role to play in any and all these three legs.
The efficacy and efficiency of thermoelectrics is reflected in the figure of
merit ZT, which is directly proportional to the power factor (comprising
electrical conductivity and Seebeck coefficient) and inversely proportional
to thermal conductivity (comprising carrier and lattice contributions). The
recent emergence of nanostructured thermoelectrics has ushered in a new era
for bulk thermoelectrics, which show considerable promise to enhance the
``contra-indicating'' parameters of high electrical conductivity and low
thermal conductivity. This is achieved by introducing nanostructures in bulk
thermoelectric host materials to significantly reduce lattice thermal
conductivity via effective scattering of heat carrying phonon through
hierarchical architecture of nanostructured thermoelectrics.
The presentation will cover recent developments, current research in our
EFRC and future prospects for high performance bulk materials. Systems based
on lead chalcogenides (e.g., PbTe, PbSe, PbS) present key science challenges
with promising properties and are given particular emphasis. We have
achieved excellent control of synthesis and crystal growth of such materials
resulting in record enhancements in the figure of merit. These enhancements
derive from very large reductions in lattice thermal conductivity possible
with nanostructuring. We have experimentally realized concurrent synergistic
effect of phonon blocking and charge transmission via the endotaxial
placement of nanocrystals in thermoelectric material host.
In particular, we have shown that the enhanced performance is due to
nanostructuring of thermoelectric host matrix, with a compelling influence
of hierarchy of length-scales associated with these systems. The
presentation will outline possible future strategies for enhancing the
thermoelectric figure of merit of bulk thermoelectric materials.
*This work is supported as part of the Revolutionary Materials for Solid State Energy Conversion, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001054
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2012.MAR.A17.4