Challenges and Opportunities in Thermoelectric Energy ...Arun Majumdar, UC Berkeley Majumdar,...
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Arun Majumdar, UC Berkeley Challenges and Opportunities in Thermoelectric Energy Conversion Arun Majumdar Department of Mechanical Engineering University of California, Berkeley Materials Sciences Division Lawrence Berkeley Lab DOE, NSF, ONR, NASA
Transcript of Challenges and Opportunities in Thermoelectric Energy ...Arun Majumdar, UC Berkeley Majumdar,...
Arun Majumdar, UC Berkeley
Challenges and Opportunities in Thermoelectric Energy Conversion
Arun Majumdar
Department of Mechanical EngineeringUniversity of California, Berkeley
Materials Sciences DivisionLawrence Berkeley Lab
DOE, NSF, ONR, NASA
Arun Majumdar, UC Berkeley
Thermoelectricity and Energy Conversion
ab
V
T1 T2
aSeebeck Coefficient, S = V/∆T
Peltier Coefficient, π = Q/I=ST
pnpn
R
Qin
Qout
Qin
Tcold
Thot
pnpn
QoutI
V
Arun Majumdar, UC Berkeley
Thermoelectric Figure of Merit
Arun Majumdar, UC Berkeley
Arun Majumdar, UC Berkeley
Arun Majumdar, UC Berkeley
Courtesy: Gang Chen
Arun Majumdar, UC Berkeley
Origins of Thermoelectricity
Arun Majumdar, UC Berkeley
Effect of Nanostructuring on S2σ
(Dresselhaus et al., 1993)
Arun Majumdar, UC Berkeley
Majumdar, Science 303, 777 (2004)
PbSeTe/PbTe QD Superlattices
Harman et al., Science 297, 2229 (2002)
AgPb18SbTe20ZT = 2 @ 800K
AgSb rich
Hsu et al., Science 303, 818 (2004)
kTSZT σ2
=
Venkatasubramanian et al. Nature 413, 597 (2001)
Bi2Te3/Sb2Te3 Superlattices2.5-25nm
kbulk = 0.49 W/m-Kkns = 0.22 W/m-K
Arun Majumdar, UC Berkeley
k [W
/m-K
]
A B
Alloy Limit
Alloy limit of thermal conductivity in crystalline materials!
Arun Majumdar, UC Berkeley
Li et al., Appl Phys Lett 83, 3186 (2003)
Deyu Li, Yiying Wu, Rong Fan, Peidong Yang
Nanowire
Si/SiGe superlattice nanowires
Arun Majumdar, UC Berkeley
ErAs Nanostructures Embedded in InGaAs
Arun Majumdar, UC Berkeley
InGaAs
ErAs/InGaAs
Woochul Kim, Pramod Reddy, Josh Zide, Art Gossard
Below Alloy Limit!
Arun Majumdar, UC Berkeley
k =
d
dTeb ω( )Planck BB1 2 3 v ω( )
Speed{ l ω( )
MeanFreePath{ dω
0
ωmax
∫⎡
⎣
⎢ ⎢
⎤
⎦
⎥ ⎥
Frequency, ω ωmax
eb
v
Atoms/Alloys
Nanostructures
Phonon Scattering
Hypothesis
Arun Majumdar, UC Berkeley
Courtesy: Ed Croke, Hughes Res. Lab. for materials
Si-Ge Superlattices
Arun Majumdar, UC Berkeley
Cathode
Barrier
Anode
Metallic contact for
top connection
100 microns
Courtesy: John Bowers (UCSB); Ali Shakouri (UCSC)
SEM Picture of Thin Film Coolers
Arun Majumdar, UC Berkeley
X. Fan, G. Zeng, C. LaBounty, E.Croke, C. Ahn, J.E. Bowers, A. Shakouri, “SiGeC/Si superlattice micro cooler,” Applied Physics Lett., Vol. 78, No.11, 12
March 2001.Featured in Nature Science Update, Physics Today, AIP April 2001
n-Si/SiGeC Superlattice Micro Cooler
Arun Majumdar, UC Berkeley
G. Zeng, X. Fan, C. LaBounty, J.E. Bowers, E.Croke, J. Christofferson, D. Vashaee, A. Shakouri, “Direct Measurement of Cooling Power Density for Thin Film Suplerlattice Micro Coolers,” submitted to APL 2002.
Micro Refrigerator Integrated with Thin-Film Heater
Arun Majumdar, UC Berkeley
Localized control of temperature on the chip.
InP-based Micro Refrigerator & Micro Heater
Arun Majumdar, UC Berkeley
Nanowire Array Composites and Devices
2 µm
200 nm
Majumdar Lab, UC Berkeley
Arun Majumdar, UC Berkeley
Majumdar, Science 303, 777 (2004)
