2371-9

Advanced Workshop on Energy Transport in Low-Dimensional Systems: Achievements and Mysteries

Ali SHAKOURI

15 - 24 October 2012

Birck Nanotechnology Center, Purdue University West Lafayette

U.S.A.

Nanostructured Materials for Thermoelectric Energy Conversion

N t t d t i l fNanostructured materials for thermoelectric energythermoelectric energy

conversion

DOE/EFRC (CEEM Center), DARPA, ONR, AFOSR, NSF, SRC-IFC, CEA, Intel, Wyle Lab

CO2 Emission Goals (2000-2100)

IPCC

World Energy Use in 2005 (15TW)

E S

Nuclear 6%

Renewables, 6%

Energy Sources

Biomass, 11%

Nuclear, 6%

Gas, 20%

Coal, 27%

Oil, 32%

Energy

P l ti (billi )Population (billions)

Individual Emissions (2030)

Direct Conversion of Heat into ElectricityDirect Conversion of Heat into Electricity

ElectricalHot Cold

TVS

Seebeck coefficient(1821)

V~ S T

Electrical ConductorT(1821)

2

V~ S T

2

2

kSZ Rload = RTE internal

)()()( 2

tyconductivithermaltyconductivielectricalSeebeckZ

PeltierPeltier Effect (1834)Effect (1834)

bb b

Qa

ba

ab a b I

S TdSdT T

Commercial TE Module

Thermoelectric EffectsThermoelectric Effects

SVT

ab

aT

ab a b

QI

S TdSa

baI dS

dT T

Q b

I T

Power Generation Efficiencies

K. Yazawa and A. Shakouri, J. Appl. Phys. 111, 024509 (2012)

C. Vining, “Th“Thermo-electric Process”, MRS Spring p g1997 (Vol. 478, p.3)

Efficiency at maximum output power

+= 1 – 2Ta/(Ts+Ta)

ncy -= Carnot /2

aT1

Eff

icie

n

s

a

T1limit

E

T /TTa/TsK. Yazawa and A. Shakouri, J. Appl. Phys. 111, 024509 (2012)

Carnot Cycle (reversible)

Heat In

Heat OutHeat Out

Curzon-Ahlborn Limit

Am. J. Phys4343

aT1s

a

T1limit

Cronin Vining, ZT Services

Hot Shoe (Mo-Si)

B-doped Si0.78Ge0.22

P-doped Si0.78Ge0.22

B-doped Si0.63Ge0.36

P-doped Si0.63Ge0.36

Cold Shoe

n-type legp-type leg

Cronin Vining, ZT Services

Typical Distributed Feedback Laser:/ T= 0.1 nm/oC

Heat generation kW/cm2Heat generation kW/cm2

Cronin Vining, ZT Services

Thermoelectric FigureThermoelectric Figure--ofof--Merit (Z)Merit (Z)

SS2

E

Microscopic Origin of Thermoelectric Cooling

E E

Material (b)

E

Material (a)

Cooling at the Junction within electron energy

Fermi

gyrelaxation length

STFermi Energy

Thermal Nanosystems andNanosystems and

Nanomaterials

’(E)(E)Differential Conductivity

Intuitive Picture

EnergyEnergy

Ef

f(E) v(E) (E)n(E) (E)( ) ( )n(E) ( )

(E)dE

1 (E)(E E )dE

(E) 2 (E) 2(E) (E)(feq )

S1eT

(E)(E EF)dE

(E)dEE Ef

vx

n

feq

(E) e2 (E)v x2(E)n (E)(

feq

E)

Low Dimensional Low Dimensional ThermoelectricsThermoelectrics

2D

Energy

1D

0D

Density-of-States

Calculated ZT of Bi quantum well and quantum wire

Dresselhaus, MS; Dresselhaus, G; Sun, X; Zhang, Z; Cronin, SB; Koga, T;Dresselhaus, MS; Dresselhaus, G; Sun, X; Zhang, Z; Cronin, SB; Koga, T; Ying, JY; Chen, G; Microscale Thermophysical Engineering, 1999,V3:89-100.

Science 303

T. C. Harman (2002) and R. Venkatasubramanian (2001)T. C. Harman (2002) and R. Venkatasubramanian (2001)

Vineis et al Advanced

PbTe/PbTeSe Quantum DotSuperlattices

Vineis et al Advanced Materials

p

Quaternary: ZT=2T=43.7 K

T=32.2 K, ZT ~2-2.4T.C. Harman, Science, 2002

,R. Venkatasubramanian, Nature, 2001

Nanostructure BulkPbTe/PbSeTe Bi2Te3/Sb2Te3 Superlattice Bulk

Power Factor ( W/cmK2) 25.5 28 40 50.9Thermal Conductivity (W/mK) 0.5 2.0 0.5 1.26

(From M. S. Dresselhaus, Rohsenow Symposium, 2003)

N tNature

Seebeck –Conductivity Trade off

EEbarrier

Deg Semiconductor/Metal + Energy Filter (Thermionic emission)Deg. Semiconductor/Metal + Energy Filter (Thermionic emission)

A. Shakouri, “TE, thermionic and thermophotovolt. energy conversion”, ICT 2005

Thermionic Energy Conversion CenterAssume: lattice=1W/mK, mobility ~10 cm2/Vs

Engineering current and heat flow in

Non-conserved

Assume: lattice 1W/mK, mobility 10 cm /Vs

Metal/Semiconductor Nanostructure

metal/semiconductor nanostructures

T

(Eb

arrier -

Non-conservedNanostructure

Goal: efficiency > 20-30% (ZT>2.5)

ZT -E

f ) / kB T

UCSCBerkeley

T

ConservedPlanar BarrierD. Vashaee, A. Shakouri, Phys. Rev. Lett., 2004

BSST Inc.Delaware

Fermi Energy (eV)

Harvard MIT

ONR (2003-2010), DARPA (2008-2012)

Harvard MITPurdue UCSB

Metal/ Semiconductor Multilayers for TEs

Purdue

HAADF STEM

In,GaAsEr

11nm

L d Sh t W l th Ph S tt i

Beating the Alloy Limit in Thermal Conductivity

Long and Short Wavelength Phonon ScatteringThermal Conductivity Reduction

6

3

0

W. Kim, J. Zide et al. Physical

Review Letters 2006

0 200 400 600 8000 2006

kkk

cycycyF

req

uen

Fre

qu

enF

req

uen

a

kWavevector a

kWavevector a

kWavevectorNanoparticle aaa

W. Kim, et al. Physical Review Letters 2006

Zide et al. J. of Applied Physics (2010); Burke, Bahk, et al. to be published (2012)

CrossCross--plane and inplane and in--plane plane SeebeckSeebeck in thick in thick barrier barrier superlatticessuperlattices InGaAs:ErAsInGaAs:ErAs//InGaAlAsInGaAlAs

Cross plane

Al

Cross-plane (with filtering)

In-plane

Zide et al, PRB 74, 205335, 2006

Solar Cells

AADOE/EFRC CEEM Center

AE

Substrates

ElectrodesThermoelectric

Leg thickness

ThermoelectricModule

NP

current

Cold sideHeat exchanger

Coolant

g

Components of TE system (cost per unit area)

DOE/EFRC CEEM CenterDOE/EFRC CEEM Centerer

ou

tpu

t p

er p

ow

e[$

/W]

eria

l co

st [

Uh

Mat

e

Yazawa & Shakouri; Journal of Material Research 2012

Uc Uc/UhZT

ncy

k

ncy

k

ncy

k

Fre

qu

eF

req

ue

Fre

qu

e

a

kWavevector a

kWavevector a

kWavevector

Natalio Mingo ,

Frequency-Dependent Thermal Conductivity

Th l i d h12kl fThermal penetration depth 2 ml f

C

measurementsmeasurements

SAMPLE THICKNESS (UDEL)

SAMPLE THICKNESS (UCSB)( )

FREQUENCY-DEPENDENT THERMAL CONDUCTIVITY

InGaAsm

K)

0.3%ErAsity (W

/m

0.3%ErAs

ondu

ctiv

i

1.8%ErAs

herm

al C

oTh

Frequency (MHz)Gilles Pernot, H. Lu, P. Burke et al., MRS 2012

C. Jeong and M. LundstromLundstrom (Purdue)

Annual Review of Materials Research,

AcknowledgementResearch Professors: Zhixi Bian Kaz YazawaResearch Professors: Zhixi Bian, Kaz Yazawa

Postdocs/Graduate Students: Kerry Maize, Hiro Onishi, Tela Favaloro, Phil Jackson, Oxana Pantchenko, Amirkoushyar Ziabari, Bjorn V h J H B hk Y R i K hVermeersch, Je-Hyeong Bahk, Yee Rui Koh

Collaborators: John Bowers, Art Gossard (UCSB), Tim Sands, Yue Wu (Purdue), Rajeev Ram (MIT), Venky Narayanamurti (Harvard), Arun ( ), j ( ), y y ( ),Majumdar (Berkeley/ARPA-E), Josh Zide (Delaware), Lon Bell (BSST), Yogi Joshi, Andrei Federov (Georgia Tech), Kevin Pipe (Michigan), Stefan Dilhaire (Bordeaux), Natalio Mingo (CEA), Mike Isaacson, Sriram Shastry, Joel Kubby, Ronnie Lipschutz, Melanie Dupuis, Ben Crow, Steve Kang (UCSC), Bryan Jenkins, Susan Kauzlarich (Davis)

Alumni: Younes Ezzahri (Prof. Univ. Poitier), Daryoosh Vashaee (Prof. ( ), y (Oklahoma State), Zhixi Bian (Adj. Prof. UCSC), Mona Zebarjadi (Prof. Rutgers), Yan Zhang (Tessera), Rajeev Singh (PV Evolutions), James Christofferson (Microsanj), Kazuhiko Fukutani (Canon), Je-Hyoung Park (Samsung) , Javad Shabani (postdoc, Harvard), Xi Wang (InterSil), Helene Michel (CEA), Gilles Pernot (Bordeaux), Ramin Sadeghian (H2scan), Shila Alavi (UCSC ASL), Tammy Humphrey, David Hauser