Quant-ph 20180511 Resolving Contradictory Transport Requirements in Thermoelectric Materials

by David J. Singh (Department of Physics & Astronomy, University of Missouri, USA)

Friday 11 May 2018, 10:00 → 10:30 Asia/Shanghai

Meeting Room 410,TDLI（Tsung-Dao Lee Library）

Abstract

Thermoelectric devices are used for the conversion of thermal and electrical energy. They offer a number of advantages over competing technologies including scalability to small sizes and temperature differences, simple reliable designs and often low cost. However, they have not seen wide application in energy applications due to their limited conversion efficiency. This is a consequence of the limited performance of current thermoelectric materials, which can be characterized by a dimensionless figure of merit, ZT=σS2T/κ. There is no known fundamental limit on ZT. However, the combination of transport parameters entering ZT is a contradictory combination that does not occur in ordinary materials. Electronic structure plays a remarkably subtle role in thermoelectric performance that can however be simply visualized in terms of iso-energy surfaces. A long sought connection is drawn between topological insulators and high ZT thermoelectrics, explaining the overlap between these two interesting materials classes. Characteristics that can be used to identify new thermoelectric compositions are discussed and an efficient computational screening method based on an electronic fitness function is presented.

Biography

EDUCATION:
1980: B.Sc (Physics), Summa cum Laude, University of Ottawa, Canada.
1985: Ph.D. (Physics), University of Ottawa, Canada.
EMPLOYMENT:
2017-present Curators’ Professor, University of Missouri.
2015-present: Professor, Physics & Astronomy, University of Missouri.
2004-2015: Group Leader, Corporate Fellow, Oak Ridge National Laboratory.
1998-2004: Head, Theory of Functional Materials Section, Naval Res. Lab.
1990-2004: Research Physicist, Naval Research Laboratory.
1988-1990: National Research Council Associate, Naval Research Laboratory.
1985-1988: Postdoctoral Fellow of H. Krakauer, College of William & Mary.
OTHER POSITIONS:
American Physical Society, Division of Computational Physics, Executive Committee, 2010-2013. APS Publications Oversight Committee, 2009-2012.
Editorial Board: New Journal of Physics, Phase Transitions, Functional Materials Letters, Scientific Reports.
Associate Editor, Materials Today Physics.

Division

Condensed Matter