Thermoelectrics Team

The Caltech Thermoelectrics Team

2009 Thermoelectrics Group Party

Old photos 2007


Directions to Caltech Thermoelectrics Laboratory	Thermoelectrics Group Meetings: Thursdays in Steele 110 check outside 319 Steele for updates

Group Members

Jeff Snyder Is a Faculty Associate in the Materials Science Department at Caltech. He was a Senior Member of the Technical Staff in the thermoelectrics group at JPL for 9 years (1997-2006). He received his B.S. in physics, chemistry and mathematics at Cornell University and his Ph.D. in applied physics from Stanford University (1997) where he was a Hertz Fellow. His research interests include Solid State Chemistry, Physics and Engineering of thermoelectric and other energy materials. His current research focuses on Thermoelectric Materials and Engineering of Thermoelectric Devices. Since joining JPL/Caltech in 1997, Dr. Snyder has been investigating novel thermoelectric materials including antimonide Zintl phases, such as Yb14MnSb11 and Zn4Sb3, and nanostructured thermoelectric composites. He has developed capabilities for high temperature transport properties measurements of bulk materials. He has implemented novel empirical and analytical models for efficient power generation and spot cooling for both bulk and thin film devices. He has designed and tested elecrochemical MEMS micro-thermoelectric devices, portable power sources and energy harvesting systems for terrestrial and space applications. He has also participated as a consultant on a number of thermoelectric projects. Dr. Snyder has over 100 publications on thermoelectric materials, devices and applications. Dr. Snyder is a board member for the International Thermoelectric Society, organizer of the Materials Research Lectures at Caltech, and has been an Adjunct Professor at Cal Poly Pomona teaching MTE208 Electronic Materials.

Dr. Snyder's previous areas of research include Colossal Magnetoresistance materials and Metallic Ferromagnets (Stanford University) which involved materials synthesis, thin film deposition, and design, automation and analysis of electronic and magnetic measurements. At the Max Planck Institut für Festkörperrperforschung, Stuttgart, Germany (1992-93) he studied Intermetallic, Sub-nitride, and C60 intercalation solid state chemistry. At Cornell (1990-91) he studied chalchogenides.

Teruyuki Ikeda
Dr. Teruyuki Ikeda recieved Dr. Eng. degree from Kyoto University (2000) for a study on thermodynamics, defects, and diffusion in intermetallic compounds. He worked with fabrication and mechanical properties of porous metals when he was a Research Associate at the Institute of Scientific and Industrial Research of Osaka University (1999 - 2004). Since joining Caltech in 2004 he has been studying nanostructuring of bulk thermoelectric materials utilizing various sorts of phase transformations. Since 2008, he has been a PRESTO Researcher of Japan Science and Technology Agency.

Postdocs

Eric Toberer

Eric S. Toberer is a Beckman Institute Postdoctoral Scholar in Materials Science. He earned his BS in Chemistry in 2002 from Harvey Mudd College in Claremont, California. Eric then spent four years working with Ram Seshadri in the Materials Department at the University of California, Santa Barbara in the area of porous inorganic materials. Since joining the Thermoelectrics group at Caltech he has worked on a number of thermoelctric material systems related to Zintl Phases such as Yb14MnSb11, Clathrates, LiZnSb, SrZn2Sb2, and Zn4Sb3.

Yanzhong Pei

Yanzhong Pei received his Ph. D from Shanghai Institute of Ceramics, Chinese
Academy of Sciences in 2008. He also spent a year at Michigan State
University as a Visiting Research Associate in 2008. He had several years
experience on synthesis and transport properties of thermoelectric materials
especially on filled CoSb3 Skuterudite. He joined TE group at Caltech as a
Postdoctoral Scholar in Materials Science, mainly to work on nano-structured
composites for waste heat recovery thermoelectric applications.

Ali Saramat

Ali Saramat received his B.S. from Boras University Collage and M.S. and Ph.D. from Chalmers University of Technology (2007) in Goteborg, Sweden.
At Caltech, Ali Saramat has been working on the preparation and characterization of new thermoelectric materials based on clathrates.

Graduate Students

Andrew (Drew) May

Drew is studying the solid state physics of thermoelectric transport in a variety of bulk materials. During his first years at Caltech, he focused on La3-xTe4, a high temperature material of interest to NASA/JPL. After the development of a mechanical alloying synthesis procedure that allowed reliable control of stoichiometry and optimization of thermoelectric efficiency, a detailed analysis of the transport data suggested multiple bands were influencing transport. Collaboration with David Singh of Oak Ridge National Lab confirmed the multi-band features and the calculations revealed the qualitative behavior observed by experiment. A similar experimental study was performed on the type-I clathrate Ba8Ga16-xGe30+x, which revealed transport could be well described by a single parabolic band model for the n-type compositions with large thermoelectric performance. In other work, analysis of the thermal transport of SrZnSb2 and SrZn2Sb2 suggested that the larger unit cell of SrZnSb2 resulted in lower lattice thermal conductivity due to a smaller volumetric heat capacity of the heat-carrying, acoustic phonons. We believe this concept offers a simple explanation for the low lattice thermal conductivity in a variety of thermoelectric materials with large unit cells.

Alex Williams

Heng WANG

Heng is studying the synthesis of Bi2Te3 based thermoelectric materials and optimizing thermoelectric properties via introducing impurity levels to the band structure

Nick Heinz

Nick is studying the microstructure of nanostructured thermoelectrics by Transmission Electron Microscopy (TEM) in collaboration with Sandia Laboratories.

Gregory Pomrehn

Greg is studying phase stability of Zn4-Sb3 from first principles thermodynamics (in collaboration with Prof. Axel van de Walle) and validating the results with experiments to detect the phase boundaries.

Affiliated Caltech Faculty

Sossina M. Haile

Vilupanur Ravi - Cal Poly Pomona

Former Members

Prof. Hirokazu Tatsuoka (Visiting Faculty), Shizuoka University, Japan

Frank Gascoin (postdoc), U. Montpellier, France

Richard Blair (JPL postdoc) , U. Central Florida

Exchange Students

Silvan Gariel, Ecole des Mines de Paris, France (2008)

Espen Flage-Larsen (Ph. D.), University of Oslo, Norway (2009)

Kasper Borup, Aarhus University, Denmark (2010)

Collaborators from the Jet Propulsion Laboratory

Directions to JPL Thermoelectrics Laboratory

Jean-Pierre Fleurial has been group supervisor of the Materials and Device Technologies group at JPL which includes the Thermoelectrics Team. Dr. Fleurial earned his Ph.D. in solid state physics and materials science from the National Polytechnique Institute of Lorraine, France, in 1988. During his Ph.D., he developed new growth techniques and theoretical models demonstrating that high quality single crystals of Bi2Te3 can have ZT values close to those usually achieved only with solid solutions. In 1988, Dr. Fleurial came to JPL as a National Research Council Resident Research Associate and joined the permanent staff in 1990. He was first involved with the optimization of Si-Ge alloys for thermoelectric power generation. He has calculated ternary and quaternary phase diagrams of Si-Ge alloys with dopants, and also performed diffusion and solid solubility studies, liquid phase epitaxial growth of Si-Ge. More recently, Dr. Fleurial has been actively involved with the study of novel promising thermoelectric materials, in particular compounds with the skutterudite structure. Dr. Fleurial has served on the board of the International Thermoelectric Society.

Thierry Caillat is a senior member of the technical staff at the Jet Propulsion Laboratory/California Institute of Technology and task leader for the JPL Thermoelectrics Team. He received his Ph.D. in Materials Science in 1991 from the National Polytechnique Institute of Lorraine, France. He then received a National Research Council Fellowship to study new materials for thermoelectric applications at the Jet Propulsion Laboratory. He joined the permanent staff at JPL in 1994. His primary research interests have focused on the identification and development of new thermoelectric materials and devices. He has developed transport properties models to optimize these materials for thermoelectric applications. In the last five years, he has played a key role in identifying several families of thermoelectric materials with superior thermoelectric properties, including skutterudites and b-Zn4Sb3-based materials. More recently, he has been involved in the studies of the integration of some of these new materials into advanced, segmented unicouples with superior performance. He is the author of over 30 articles in refereed technical journals and over 40 articles in technical conference proceedings. Dr. Caillat holds two patents on new thermoelectric materials and has two patents pending on new thermoelectric devices.
Dr. Caillat is chairman for the International Conference on Thermoelectrics in 2002 and has served on the International Advisory Board and Technical Program Committee of many International Conferences on Thermoelectrics since 1996. He has organized and chaired many sessions on thermoelectrics in various national and international conferences since 1993.

Chen-Kuo Huang received his B.S. in Materials Science and Engineering, National Tsing-Hua University (1978), M.S. in Materials Science and Engineering, National Tsing-Hua University (1980), and Ph.D. in Materials Science and Engineering, Stanford University (1988). Dr. Huang is a senior member of the technical staff at the Jet Propulsion Laboratory/California Institute of Technology.

Collaborators outside JPL-Caltech