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HEATER Seminar Series: Ali Shakouri, Purdue University

Nanoscale thermal transport and thermoelectric energy conversion
When Mar 14, 2014
from 10:10 AM to 11:00 AM
Where BA B024, Bahen Centre, 40 St. George St
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Ali Shakouri

Birck Nanotechnology Center

Purdue University, West Lafayette, IN

Energy consumption in our society is increasing rapidly. A significant fraction of the energy is lost in the form of heat. In this talk we introduce thermoelectric devices that allow direct conversion of heat into electricity. Novel metal-semiconductor nanocomposites are developed where the heat and charge transport are modified at the atomic level [1]. Potential to increase the energy conversion efficiency and bring the cost down to $0.1-0.2/W will be discussed. We then focus on nanoscale thermal and thermoelectric transport. Full field transient thermal imaging with submicron spatial and 800ps time resolution is used to study ultrafast Peltier cooling and Joule heating. Finally, we describe some of the recent studies of ballistic heat conduction. We show that non-Fourier diffusion equation can better describe heat propagation in submicron semiconductor alloys. This has important implications in the design of high power and high speed electronic and optoelectronic devices.

 

[1] Thermoelectricity: from Atoms to Systems (https://nanohub.org/courses/TEAS) a nanoHUB-U course.

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Ali Shakouri is the Mary Jo and Robert L. Kirk Director of the Birck Nanotechnology Center and a Professor of Electrical and Computer Engineering at Purdue University. He received his Engineering degree from Telecom Paris, France in 1990 and Ph.D. from California Institute of Technology in 1995. His current research is on nanoscale heat and current transport in semiconductor devices, high resolution thermal imaging and waste heat recovery systems. He is also working on a new interdisciplinary sustainability curriculum in collaboration with colleagues in engineering and social sciences. He received the Packard Fellowship in Science and Engineering in 1999 and the NSF Career award in 2000.

HEATER Seminar Series: Xianfan Xu, Purdue University

Thermoelectrics for Automobile Waste Heat Recovery
When Apr 08, 2014
from 02:10 PM to 03:00 PM
Where BA B024, Bahen Centre, 40 St. George St
Contact Name
Contact Phone 416-946-8503
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Xianfan Xu

School of Mechanical Engineering

Purdue University, West Lafayette, IN

Recent advances in the improvements of thermoelectric materials promise a wider range of practical applications. One of the potential deployments is waste heat recovery from automobile exhaust gas. A large percentage (60%) of energy is wasted to the environment through the hot exhaust gas of an automobile engine. Using thermoelectric generators (TEGs), part of the waste heat can be recovered into usable form, resulting up to 10% benefits in fuel economy.

The development of an efficient TEG requires a multidisciplinary, multi-scale approach in thermal and materials sciences, ranging from atomic scale materials design and thermal transport analysis, to the impedance matching in each thermoelectric module, to the design of heat exchangers to efficiently deliver and remove heat from thermoelectric modules. In this presentation, I will describe research efforts at Purdue, which is in collaboration with the General Motors Global Development and Research (Warren, MI, USA) and a number of commercial companies and national laboratories, to develop TEGs for automobile vehicles. The on-going researches are (1) development of nano-engineered thermoelectric materials and heat transfer analysis including atomic scale materials design and simulation and experimental ultrafast phonon spectroscopy, (2) development of nanoscale thermal interface materials and advanced ultrafast laser based characterization techniques, (3) design and optimization of TEG topology for maximum energy output.  

Biography: Xianfan Xu is James J. and Carol L. Shuttleworth Professor of Mechanical Engineering at Purdue University with a courtesy appointment in Electrical and Computer Engineering. He obtained his B.Eng. degree in Engineering Thermophysics from the University of Science and Technology of China (1989), and M.S. (1991) and Ph.D. (1994) degrees in Mechanical Engineering from the University of California, Berkeley. His current research is focused on ultrafast and nanoscale optics and their applications in energy transfer/conversion studies and nano-materials manufacturing. He is the recipient of the National Science Foundation Faculty CAREER Award and the Office of Naval Research Young Investigator Award, and is the recipient of GM Faculty Fellowship, B.F.S. Schaefer Young Faculty Award, and Discovery in Mechanical Engineering Award.  He was elected Fellow of the American Society of Mechanical Engineers in 2006 and Fellow of SPIE in 2009. 

Professional Development Workshop: Knowledge Translation

When Mar 24, 2014
from 10:00 AM to 12:00 PM
Where Career Centre Seminar Room, 214 College Street, Toronto
Contact Name
Contact Phone 416-946-8503
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This pilot project workshop will address the issue of Knowledge Translation, speaking to why it is important for research scientists and how it is done. 

Thermoelectrics Summer School 2014

Thermoelectrics Summer School 2014 at the University of Toronto
When Jul 11, 2014 09:00 AM to
Jul 12, 2014 05:00 PM
Where BA 1230, Bahen Centre, 40 St. George St
Contact Name
Contact Phone 4169468503
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Bringing experts from academia and industry together with trainees and collaborators, the School provides a unique training opportunity. With Professional Development workshops and research presentations for students, this is an unparalleled opportunity for students to grow as researchers and connect with leaders in the field of thermoelectrics. 

For details of the School and to register, please visit our website at https://heater.physics.utoronto.ca/seminar-series/summer-school-2014/ and contact Erin Macnab (heater@physics.utoronto.ca or 416-946-8503) with the registration details.

There is no registration cost for the School. 

There will be a poster session. All participants are welcome to bring their poster. If you plan on participating in the poster session, please email Erin Macnab at heater@physics.utoronto.ca before July 1, 2014.

HEATER Seminar Series: Kefeng Cai, Tongji University

Research Progress in Polymer and Polymer Based Thermoelectric Materials
When Aug 11, 2014
from 10:00 AM to 11:00 AM
Where MP 606
Contact Name
Contact Phone 416-946-8503
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Kefeng Cai

Tongji University 

Shanghai, China

In this presentation, background related to thermoelectrics, including thermoelectric effects, thermoelectric conversion efficiency and applications of thermoelectric devices will be briefly introduced. Important research progress in the field of thermoelectrics, including new concepts, new material systems, with a focus on polymer and polymer based thermoelectrics during the last decade will follow. Finally, research progress in conducting polymers (e.g. PEDOT:Tos:PPP) and conducting polymer-inorganic nanostructure composites (including PANI/PbTe, PANI/Ag2Te, PEDOT/Ag(Cu), PEDOT/PbTe, PEDOT:PSS/Bi2Te3PEDOT:PSS/graphene, and PPY/carbon nanotubes) will be described. Prof. Cai’s research group will also be introduced. 

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Prof. Kefeng CAI received his B.S. and Ph.D. from Wuhan University of Technology (PR China) in 1987 and 1998, respectively. He worked on Materials Synthesis and Processing at the State Key Laboratory of Advanced Technology, Wuhan University of Technology from 1987 to 2001 (as an associate professor since 1995). He was a Postdoctoral fellow from February 1999 to January 2001 at Physics Department, University of the Witwatersrand, South Africa, worked as an Alexander von Humboldt Research Fellow from August 2001 to December 2002 at Materials Research Institute, German Aerospace Center, and was a senior visiting scholar at CSIRO, Australia from July to August 2012. He joined Tongji University as a professor since 2003. He is interested in thermoelectrics and synthesis and characterization of nanomaterials. Currently he is a member of International thermoelectric society and senior member of American Nanosociety, and he is also an Editorial Board member of Global Journal of Physical Chemistry and World Journal of Nano Science and Engineering. He has published more than 80 research journal papers, two review papers and 10 patents.


Professional Development Workshop: Establishing Your Career Identity

When Oct 06, 2014
from 02:00 PM to 04:00 PM
Where Career Centre Seminar Room, 214 College Street, Toronto
Contact Name
Contact Phone 416-946-8503
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The first workshop in the HEATER Professional Development Curriculum will engage with the following points: Identifying the career-related value of graduate student's skills and strengths; Introduction of four career development capacities models; Related activities 

All graduate students are welcome; register by September 29 by emailing heater@physics.utoronto.ca 

Professional Development Workshop: Making Connections

When Nov 03, 2014
from 02:00 PM to 04:00 PM
Where Career Centre Seminar Room, 214 College Street, Toronto
Contact Name
Contact Phone 416-946-8503
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The second workshop in the HEATER Professional Development Curriculum will highlight the importance of networking, outline events and resources available for networking and teach networking skills and strategies.

 

All graduate students are welcome; register by October 27 by emailing heater@physics.utoronto.ca 

HEATER Seminar and CINS Keynote Speech: Olivier Delaire, Oak Ridge National Laboratory

Phonon Scattering Mechanisms in Thermoelectrics
When Nov 14, 2014
from 05:00 PM to 06:00 PM
Where BA 1220, Bahen Centre, 40 St. George St
Contact Name
Contact Phone 416-946-8503
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Olivier Delaire

Oak Ridge National Laboratory

Oak Ridge, Tennessee

 

In order to achieve a detailed microscopic understanding of heat transport in thermoelectrics, a detailed knowledge of the phonon mean-free-paths is needed. We use neutron and x-ray scattering techniques to probe the phonon dispersions and scattering rates across the entire Brillouin zone. Neutron spectrometers can efficiently map phonon excitations throughout reciprocal space, providing critical information about the many possible phonon scattering mechanisms, including anharmonicity, electron-phonon coupling, and scattering by defects or nanostructures. X-rays enable complementary phonon measurements, and also reveal details of the nanostructure through the diffuse scattering. These neutron and x-ray measurements are complemented with bulk transport measurements and first-principles simulations to establish an atomistic understanding of phonon scattering mechanisms, and their effect on thermal conductivity. I will present investigations of phonons in several important thermoelectric materials, including PbTe, SnTe, and AgSbTe2, establishing a microscopic understanding of their thermal conductivity [1,2,3]. These insights suggest avenues to improve the performance of thermoelectric materials.

[1] J. Ma*, O. Delaire*, A. F. May, C. E. Carlton, M. A. McGuire, L. H. VanBebber, D. L. Abernathy, G. Ehlers, Tao Hong, A. Huq, Wei Tian, V. M. Keppens, Y. Shao-Horn, and B. C. Sales, Nature Nanotechnology 8, 445 (2013).

[2] C.W. Li, O. Hellman, J. Ma, A.F. May, H.B. Cao, X. Chen, A.D. Christianson, G. Ehlers, D.J. Singh, B.C. Sales, and O. Delaire,  Physical Review Letters (2014).

[3] O. Delaire, J. Ma, K. Marty, A. F. May, M. A. McGuire, M.-H. Du, D. J. Singh, A. Podlesnyak, G. Ehlers, M. Lumsden, B. C. Sales, Nature Materials 10, 614 (2011).

Funding from the US DOE, Office of Basic Energy Sciences, Materials Science and Engineering Division, and as part of the S3TEC EFRC. Modeling of neutron data in CAMM was funded by the U.S. Department of Energy, Basic Energy Sciences, Materials Sciences and Engineering Division.

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Olivier Delaire obtained his PhD from Caltech in 2006 (Materials Science). His doctoral thesis investigated the role of phonons and electron-phonon coupling on the entropy of crystalline solids, primarily in superconducting transition metal compounds. After holding postdoc and research staff positions at Caltech, he became a Shull Fellow in the Neutron Sciences Directorate at Oak Ridge National Laboratory (2008), where he started to investigate thermoelectric materials. Delaire is now a research staff in the Materials Science and Technology Division at ORNL, Scattering and ThermoPhysics Group. He is the recipient of a DOE Early Career Award (2014).

HEATER Seminar Series: Ankit Disa, Yale University

Manipulating Electronic Structure and Transport in Correlated Oxide Heterostructures
When Jan 27, 2016
from 12:10 PM to 01:00 PM
Where 60 St. George St., MP606
Contact Name
Contact Phone 416-978-7267
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January 27, 2016, 12:10 pm

60 St. George St., MP606

 

Ankit Disa, Department of Applied Physics, Yale University

In complex transition metal oxides, strong correlations between electrons lead to entangled ground states with many fascinating emergent phenomena, including magnetism and high-temperature superconductivity. Moreover, the interplay between structural, charge, spin, and orbital degrees of freedom in these systems opens up the possibility of inducing and influencing exotic phase behavior using state-of-the-art atomic layering techniques. In this talk, I describe the engineering of electronic structure and transport properties of complex oxides through atomically-precise control of dimensionality and interfacial structure using molecular beam epitaxy. Specifically, I focus on two studies related to the rare-earth nickelates, an archetypal correlated system. The first investigation concerns the thickness-induced metal-insulator transition in LaNiO3, in which we use synchrotron-based x-ray diffraction and magnetotransport to reveal the structural origin of the crossover and demonstrate the realization of two-dimensional conduction in LaNiO3 by surface engineering. The second project focuses on our ability to manipulate the orbital configuration in rare-earth nickelates. A combination of first-principles theory and synchrotron-based x-ray techniques illustrates that unique three-component heterostructuring can be used to effectively change the nickelate orbital structure to emulate that of the high-temperature superconducting cuprates, and, in fact, can tune the orbital configuration between the bulk structures. Both approaches are based on simple physical mechanisms and represent routes to explore and enhance a wide variety of orbitally-dependent phenomena in correlated oxides including metal-insulator transitions, spin switching and superconductivity.

 

Ankit Disa is a PhD candidate in Applied Physics in the group of Prof. Charles Ahn at Yale University. He received his B.S. in Applied and Engineering Physics from Cornell University in 2010.



Ankit Disa

PDF document icon Disa Seminar Poster.pdf — PDF document, 202 KB (206929 bytes)

HEATER Seminar Series: Dimitri Vasilevskiy

Recent advances in characterization of thermoelectric materials by Dimitri Vasilevskiy, Ph.D., Dr. Sc., Ecole Politechnique de Montreal, TEMTE Inc.
When Jan 12, 2018
from 02:00 PM to 03:00 PM
Where C2-361 University of Waterloo
Contact Name
Contact Phone 416-978-7267
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The dimensionless thermoelectric (TE) figure of merit ZT  (Z= a2/rl where a, r and l are, respectively, the Seebeck coefficient, the electrical resistivity and the thermal conductivity) is the main parameter which allows a comparison of the overall performance of different thermoelectric materials at different temperatures. Despite its extreme importance there are very limited possibilities to provide an accurate measurement of its value. In fact, presently, the most widely used approach separately measures each one of the components of ZT.  This approach led to a total uncertainty in ZT as high as 40-50% which is unacceptable in most scientific and industrial applications. The best accuracy of the ZT value can potentially be obtained using the Harman method. However, from the very first publications and up to the most recent the impact of parasitic heat exchange between the sample and its environment has been identified as critical for measurement accuracy. This fact has seriously reduced the application of Harman based measurements, specifically at elevated temperatures where radiation losses rapidly increase.

We will discuss a novel calibration procedure, which radically solves the problem related to the parasitic thermal phenomena. This novel two-sample system calibration (2SSC) is successfully implemented on a system (ZT-Scanner, by TEMTE Inc) developed for the simultaneous Harman based measurement of all thermoelectric parameters from 240 K to 720 K. We will show on how successfully the developed system works with different materials and sample sizes.

The general questions related to the thermoelectric materials and their application will be also discussed. 

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