2371-8

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.

Nanoscale Thermal and Thermoelectric Characterization Techniques

N l Th l dNanoscale Thermal and Thermoelectric CharacterizationThermoelectric Characterization

Techniques

Thermal Transport in Low DimensionThermal Transport in Low Dimension

Hot Cold

Measuring Power and Temperature from Real P ThProcessors The

Next Generation Software (NGS) Workshop (NGS08),

http://masc.cse.ucsc.edu

0

S b k 1 22ASnapback current =1.22A.

IRPS

atu

re

emp

era

ativ

e Te

Time (ps)

Rel

a

Time (ps)

World Marketed Energy Use1990-2035

13TW 2050: 25 30TW13TW 2050: 25-30TW

CO2 Emission Goals (2000-2100)

IPCC

P l ti (billi )Population (billions)

World Energy Use in 2005 (15TW)

Energy

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

Power Generation Efficiencies

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

Measuring voltage at nanometer scale

Measuring temperature at nanometer scale

Measuring heat flow at nanometer scale

M th d P i i lMethod Principle

Micro-thermocouple

Infrared Thermography

Liquid CrystalLiquid Crystal Thermography

Hot ElectronHot ElectronCold Electron

1 m

Si (10nm)

Appl. Phys. Lett.

Si (10nm)

Si0.89Ge0.1C0.01

Proceedings of IEEE

Si/SiGe Micro refrigerator on a chip

CathodeCathode

1 micron

BarrierMetallic

contact for top

connection

Anode

connection

100 i100 microns

Applied Physics Lett.

Micro thermocouple measurements: Cooling vs. Current

(60x60 m2 )

(oC

)MeasurementMeasurement

Co

olin

g

100

Bulk material

MeasurementThermocouple

ReferenceThermocouple

BottomContact

TopContact

MeasurementThermocouple

ReferenceThermocouple

BottomContact

TopContact

100 microns

Substrate

Emitter

Superlattice

Collector Substrate

Emitter

Superlattice

Collector

Current (mA)

SiGe/Si Superlattice CoolersTemperature Controlled

StageTemperature Controlled

Stage

Calibrated infrared imagingCalibrated infrared imaging

AMD Processor (cm) Microrefrigerator

Francisco Mesa-Martinez, Jose Renau, UCSC Vivek Sahu, Georgia Tech

M th d P i i lMethod Principle

Scanning thermal microscopy (SThM)microscopy (SThM)

Optical Interferometry

Micro Raman

Near Field Probe (NSOM)Near Field Probe (NSOM)

Scattered light intensity versus wavelength shift

Cm-1

Thermal imaging of nanostructures with a scanning fluorescent particle as a probeThermal imaging of nanostructures with a scanning fluorescent particle as a probe

Many dipoles randomly oriented

Simplicity APL 83 147 (2003)APL, 83, 147 (2003)

Infrared excitation :emission and absorption lines well separated

HOW CAN WE DEDUCE THE TEMPERATURE ? HOW CAN WE DEDUCE THE TEMPERATURE ?

E / Yb iPL spectrum of Er / Yb doped particles

Er / Yb ionsPL spectrum of Er / Yb doped particles

4F7/22H11/2H11/24S3/2 (980 nm)

(550 nm)(527 nm)

(980 nm)

).

exp(TkE

II

yellow

green

4I15/2

Thermal imaging using Fluorescence NanoparticlesThermal imaging using Fluorescence Nanoparticles

I = 50 mA

I = 0 mA

Hot spots

Uniform temperature (room temperature)

I = 0 mA

Optical contrast visible between different zones

Reference image

APL, 8 7, 184105 (2005).

InterferrometricInterferrometric measurementsmeasurements

Pogany, Gornik et al., TU Vienna 2003

Incident light Reflected light (R)

Reflected light intensity:

C

SUBSTRATE

DEVICE

Laser Probe on aLaser Probe on a micro cooler, lock-in detection at 1KHz

Lock-in imaging resultLock-in imaging result

Normalization Phase

Raw AC data Image Mask

Thermoreflectance image of microcoolerThermoreflectance image of microcooler

DC Reflection Thermal ImageC e ec o

TT (C)

Pioneering works by: Claeys FournierClaeys, Fournier, Dilhaire, Tessier,…

Transient Response 50x50 Micron Device

CCD based system:

Picosecond thermal imaging (800ps)

, Int. Heat Transfer Conf., August 2010

H e a tin g o n M e ta l A b o v e V ia

, Heat Transfer Conf., August 2010

J. Christofferson, et al, J. Electronic Packaging,130 (4) 041101, 2008

Scanning Thermal MicroscopyScanning Thermal MicroscopyScanning Thermal MicroscopyScanning Thermal Microscopy

Pt Line

Pt-Cr Junction

Laser ReflectorTip

Junction

SiNx Cantilever

Cr lineCr line

m

et al J. MEMS

Scanning Thermal Microscopy (SThM)

Tip

CantileverCantilever Mount

Pt-Crp Pt Cr Junction

Courtesy: Arun Majumdar, UC Berkeley; StefanBerkeley; Stefan Dilhaire, Univ. Bordeaux

SThM Metallic Single Wall Nanotube

T hTopography

2 K

T tipThermal images

Contact

1 m

1 nmtube 0

1 m

tube 0.45 V 0.77 V 1.2 V 1.7 V 0

Contact

Th l I 0

SThMSThM Thermal Mapping Thermal Mapping ofof MicrorefrigeratorsMicrorefrigerators

Thermal, I=0 Thermal, I=200mA

Prof. Arun Majumdar, UC Berkeley

of of MicrorefrigeratorsMicrorefrigerators

CTTT 1TC

))(,( 1 CTTyxSVDT

V S

(UT Austin)

S p-nS p-n

n pp

)105( 318 cm )101( 319 cm

mV

)

Measurement

Vo

ltag

e (m Theory

oel

ectr

ic V

Th

erm

o

Science 303

Position (nm)

Thin Film Thermal Conductivity MeasurementThin Film Thermal Conductivity Measurement

Rev. Sci. Instrum

L 2b

Thin FilmMetal line

L 2b• I ~ 1

• T ~ I2 ~ 2• R T 2

V

I0 sin( t)Substrate

• R ~ T ~ 2• V~ IR ~3

sLbkPdi

bD

kLPT

242ln

21ln

21)2( 2

fs LbkbkL 2422

David Cahill, UIUC, 2003

Modulated & delayed femtosecond laser pulse used as a PumpModulated & delayed femtosecond laser pulse used as a Pump.A Probe beam measures reflectivity variation on the surfaceThe lock-in amplifier gives the In-phase (Vin) and Out-of-phase (Vout) signals.

d)

mal

ized

R (

no

rm

Time (ps)Time (ps)

Thermal Transport in Carbon NanotubesThermal Transport in Carbon Nanotubes

Hot Coldp

• Few scattering: long mean free path l

Strong SP2 bonding: high sound velocity v

high thermal conductivity: k = Cvl/3 ~ 6000 W/m-K

• Below 30 K, thermal conductance 4G0 = ( 4 x 10-12T) W/m-K,

linear T dependence (G :Quantum of thermal conductance)linear T dependence (G0 :Quantum of thermal conductance)

Thermal Measurements of NanowiresThermal Measurements of Nanowires

Themal conductance: G = Q / (T T )

Suspended SiNx membraneLong SiNx h

(K)

1.0

1.5 T0 = 54.95 K

Themal conductance: G = Q / (Th-Ts)

g xbeams T h

0.0

0.5

0 10QI Current ( A)

-6 -4 -2 0 2 4 6

Pt resistance s (K

)

0 04

0.06

0.08

0.10

T0 = 54.95 K

Pt resistance thermometer

T s0.00

0.02

0.04

Current ( A)

-6 -4 -2 0 2 4 6, PRL 87JHT

Thermal Conductance of a NanotubeThermal Conductance of a Nanotube

APL 77APL 77

Thermal Conductivity of Carbon NanotubesThermal Conductivity of Carbon Nanotubes)

(W/m

-K

1-3 nm CVD SWCN

uctiv

ity ( 14 nm MWCN bundle

~ T 2

CVD SWCN

al C

ondu

148 nm SWCN

10 nm SWCN bundle~ T 2.5 CNT

Ther

ma 148 nm SWCN

bundle~ T 1.6

Temperature (K)

k

Li Shi, UT Austin

D id C hillDavid Cahill (UIUC)

Nano Electromechanical System (NEMS)

Thermal conductance quantization in nanoscale SiN beamsThermal conductance quantization in nanoscale SiNx beams (Schwab et al., Nature 404, 974 )

Nanoscale heat transport and microrefrigerators on a chip; A. Shakouri, Proceedings of IEEE, July 2006

J. Christofferson, et al, J. Electronic Packaging,130 (4) 041101, 2008

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