Symposium M: Unconventional thermoelectrics: from new materials to energy conversion devices

The development of advanced thermoelectric materials for effective thermoelectric devices is an evolving challenge in energy conversion technologies. The required improvement over toxic and expensive state of the art bulk semiconductor thermoelectrics needs a deep understanding of the thermoelectric conversion processes.

Scope:
The aim of the symposium is to assemble scientists from universities, scientific institutes as well as industry to promote co-operations on thermoelectric materials development. The use of solar, geothermal or waste heat as an energy source is an attractive and environmentally clean way to generate electrical power. With a thermoelectric (TE) device heat can be directly converted into electricity. TE devices work independently of mechanical and chemical conversion processes. Thus, they are emission free, noiseless, and extremely durable. A conventional TE converter has an efficiency of 5-10%. It consists of numerous thermocouples, comprising p- and n-type thermoelements connected electrically in series and thermally in parallel. Heating one side of a semi-conducting thermoelectric material allows electrons and holes to thermally diffuse along the temperature gradient and to carry their charge with them. The amount of electrical power so produced depends on the thermoelectric conversion efficiency of the device and the heat flux. The relevant material parameters, i.e., thermopower, electrical, and thermal conductivities, are interrelated by the specific electronic structure of the material. Conventional TE devices, e.g., for space applications, aim rather at high reliability than at high energy conversion efficiency and low cost. These devices are based on expensive and toxic materials like tellurides and have low temperature stability when exposed to an oxidizing atmosphere. For the future broad use, cheap and environmentally benign materials have to be found. Compounds exhibiting low heat conductivity, small resistivity, and a large Seebeck coefficient are required. Since for most materials these transport properties are interconnected by the Wiedemann-Franz-law, the development of a material breaking this relationship is the great scientific challenge to be addressed.

Hot topics to be covered by the symposium:
• Thermoelectric energy conversion
• Novel ceramic thermoelectrics
• Thin film devices
• Thermoelectric micro modules
• All oxide thermoelectric generator
• High temperature energy conversion
• Efficient conversion of solar and geothermal heat
• Perovskite-type materials
• Spin entropy
• Thermionic energy conversion
• Waste heat recovery
• Tuning of heat and electronic conductivity in solids
• …

Tentative list of invited speakers:
• I. Terasaki, Waseda University, Japan
• M. Dresselhaus, MIT
• T. Mori
• S. Hebert

Tentative list of scientific committee members:
• B. Raveau
• G. Scherrer
• R. Funahashi, AIST
• M. Rowe
• A. Reller
• MAS Subramanian

Symposium organizers:

Anke WEIDENKAFF
Empa
Ueberlandstrasse 129
CH-8600 Duebendorf-Zuerich
Switzerland
Tel: +41 44 823 4131
Fax: +41 44 823 4034
anke.weidenkaff [=at=] empa [dot] ch

Antoine MAIGNAN
CNRS
Laboratoire CRISMAT, ENSICAEN
France
Tel: +33 (0)2 31 45 26 34
Fax: +33 (0)2 31 95 16 00
antoine.maignan [=at=] ensicaen [dot] fr

Jiri HEJTMANEK
Institute of Physics of ASCR
Cukrovarnicka 10162 53
Praha 6- Stresovice
Czech Republic
Tel: +420 2 20318419
Fax: +420 2 333 43 184
hejtman [=at=] fzu [dot] cz

Hanns- Ulrich HABERMEIER
MPI Festkörperforschung
Heisenbergstr. 1
D-70569 Stuttgart
Germany
Tel: +49 711 689 1372
Fax: +49 711 689 1389
huh [=at=] fkf [dot] mpg [dot] de