Space probe to the Jupiter From JPL, NASA
Radioisotope Thermoelectric Generator (PbTe)
Introduction of Thermoelectric Materials and Moduels
1st Semester of 2012 2012.03.15, Thursday Department of Energy Science Sungkyunkwan University
Objective
The topic of energy conversion thermoelectric (TE) systems and Fundamental transport properties, Material syntheses, Efficiency evaluations, Module fabrications for practical applications etc. The physics of semiconducting thermoelectric phenomena, Seebeck and Peltier effects, Thermal conduction, the course will introduce The materials From the state-of-the-art bulk Bi-Te materials To newly developed nanostructured materials (low-dimensional systems) Hybrid system utilizing thermoelectric conversion
1 Thermoelectric Phenomena and Conversion Efficiency
2 Thermoelectric Transport Theory I : Electrical Properties
3 Thermoelectric Transport Theory II : Thermal Properties
4 Thermoelectric System : Current and Future of Modules
5 Materials Preparation : Bulk and Film
6 Measurement of Thermoelectric Properties
7 Applications : Power Generation and Heat Cooling
8 Mid-term Exam
9 Thermoelectric Materials : State-of-the-art
10 Thermoelectric Materials : Intermetallics
11 Thermoelectric Materials : Oxides
12 Thermoelectric Materials : Phonon Glass and Electron Crystal (PGEC) Materials
13 Theory and Modeling in Nanostructured Thermoelectrics
14 High efficiency in Low Dimensional Materials
15 Hybrid Energy Conversion Systems of Thermoelectrics
16 Final Exam
Plan
Textbooks
2. Thermoelectrics Handbook – Micro to Nano Edited by D. M. Rowe, 2006, Taylor & Francis.
1. CRC Handbook of Thermoelectrics Edited by D. M. Rowe, 1995, CRC Press Inc.
3. Heavily Doped Semiconductors Victor I. Fistul’, 1969, Plenum Press.
4. Thermal Physics Charles Kittel, 1969, John Wiley & Sons, Inc.
Seebeck Effect (1821) Temperature Difference Electrical Current Power Generation High Temperature Region
Peltier Effect (1834) Electrical Current Temperature Difference Heat Cooling Low Temperature Region
Thermoelectric Effect : Electrical Energy <---> Thermal Energy
Thomas Johann Seebeck (1770 – 1831)
Jean Charles Athanase Peltier (1785 – 1845)
Thermoelectric Effect : Seebeck Effect
Thermoelectric Materials
ZT=0.5
1950
1980
1990
2000
2010
ZT=2
Bi-Te, Bi-Se, Sb-Te
Pb-Te, Ge-Si, 3d Silicide
PGEC, Intermetallics, Oxide
Thin Film (Superlattice), Nanowire
Complex Structure Nanostructure Imbedded Bulk
ZT=1
ZT=0.8
Advantage
Compactness and Quietness
(No moving parts)
Available for localized heating and cooling
Environmentally friendly
Accurate Temperature control ( 0.01K )
= (T / Thot )[(1+ZTave )1/21] /
[(1+ZTave )1/2 + ( Tcold / Thot )]
Tave = (Tcold + Thot ) / 2
T = Thot Tcold
Energy Conversion Efficiency
Thermoelectric Module
Thermoelectric Materials : Efficiency
ellat
: Power Factor /2
lat : Lattice Thermal Conductivity
el : Electronic Thermal Conductivity
TZT
2
: Seebeck Coefficient (Thermoelectric Power)
: Electrical Resistivity
: Thermal Conductivity
Dimensionless Figure of Merit, ZT Trade-off
Thermoelectric Materials : Efficiency
• Black Box Cooling • Cold Chambers • Cold Plates • Compact Heat Exchangers • Constant Temperature Baths • Electronics Package Cooling • Heat Density Measurement • Integrated Circuit Cooling • Infrared Detectors • Infrared Seeking Missiles • Laser Diode Coolers • Microprocessor Cooling
• Microtome Stage Coolers • Power Generators (small) • Precision Device Cooling (Lasers and Microprocessors) • Refrigerators (Aircraft, Automobile, Boat, Hotel, Insulin, Portable/Picnic, Pharmaceutical, RV) • Semiconductor Wafer Probes • Thermal Viewers and Weapons Sights • Thermal Cycling Devices (DNA and Blood Analyzers) • Wafer Thermal Characterization • Water and Beverage Coolers • Wet Process Temperature Controller • Wine Cabinets
Blue : Cooling Red : Power Generation
Applications of Thermoelectrics
Niche Markets
Snyder, Toberer, Nat. Mater. 2008
Thermoelectric Research : Current Status
Target : High Conversion Efficiency of Thermoelectric Devices
Module : Accumulation of Elements, Contact Resistance (Welding), Shape Diversity for Micro-Scale (Thin Film)
System : Circumstance Suitability (Generation), Diversity of Mass Conversion System, Hybridization with other renewable energy system
Materials : High Efficiency (High ZT), New Materials and Various Categories (Limitation to Heavy Metal Compounds), Properties for Hybridization (Magnetic Semiconductor for Magnetocaloric) (Low Workfunction for Thermionic)
Thin Film
Cascade Conventional
Solar absorber + TE Custom Cooling Device D. Kraemer et al., Nat. Mater. 20011