Post on 13-Mar-2018
Changhee Lee, SNU, Korea
디스플레이공학 I2005. 1학기 OLED
0
Changhee LeeSchool of Electrical Engineering and Computer Science
Seoul National Univ. chlee7@snu.ac.kr
Changhee Lee, SNU, Korea
디스플레이공학 I2005. 1학기 OLED
1
Outline• Introduction to OLED displays- History of OLED display - OLED materials- OLED fabrication and color patterning- Characteristics of OLED displays and comparison with other technologies- OLED applications
• Basic physics and chemistry of organic semiconductors- Carbon, Chemical bonds, Electronic energy structure- Optical properties of organic semiconductors- Electrical properties of organic semiconductors
• OLED device physics- Carrier injection and transport- Electron - hole recombination and emission of light- Doping: fluorescent or phosohorescent dopants- Electroluminescence efficiency- OLED reliability and degradation
Changhee Lee, SNU, Korea2
디스플레이공학 I2005. 1학기 OLEDAdvantages of OLEDs
• Superior viewing performance:emissive bright colors, wide viewing angle, fast response time, and high contrast
• Excellent operating characteristics:low operating voltage, power efficient, and wide temperature range
• Good form factor:Thin, light-weight, rugged, and flexible
• Simple fabrication processes: vacuum deposition, inkjet printing, spin coating,roll-to-roll (web) processing
Vacuum Deposition
Fine Metal Shadow Mask
Substrate
Source
Ultimate Portable Communication Devices
http://www.universaldisplay.com/
Red
Ink-jetGreen
Inkjet Printing
Blue
Changhee Lee, SNU, Korea3
디스플레이공학 I2005. 1학기 OLED
Small Molecule OLED
’87 ’88 ’89 ’90 ’91 ’92 ’93 ’94 ’95 ’96 ’97 ’98 ’99 ’00 ’01 ’02
1st Polymer LEDCambridge
ITO/PPV/Al
KodakBilayer
ITO/Diamine/Alq3/Mg:Ag
PioneerQuinacridone
doping
UCSBCasting withMEH-PPV
PioneerAlLi cathode
UniaxFlexible PLED
PET/ PANI/ MEH-PPV/Ca
Linkoping U.Variable Colors from
Polymer Blend
Idemitsu Kosan CCM
TDK Poly-Si TFT
Yamagata U.White OELD
UCSB, Cambridge, UtahLasing from
Polymer Microcavitiy
Princeton U.SOLED
Seiko-EpsonInk-Jetprinting
Pioneer Full-color PMOLED
By shadow mask
Kodak LiF/Al cathode
Princeton U.Phosphorescent
OLED
SonyTop-emission
13.1” AMOLED
Polymeric OLED
’03 ’04
SDI3.6” LITIAMOLED
Seiko-Epson40” full color PLED
Ink-Jet
TMD17” full color PLED
Ink-Jet
Sanyo-KodakLTPS-TFT AMOELD
IDTech20” AMOLED
α-Si TFT
Seiko-EpsonInk-Jet
full color
SDIBoth-side emissive
2.2” AMOLEDLGE-LPL
20.1” AMOLEDLTPS-TFT
’05
SEC21” AMOLED
α-Si TFT
SDI17” AMOLED
Non-laser LTPS-TFT
KodakFluorescentdye doping
1st OLED1982
C. W. TangUSP
4,356,429
1983R. H. Partridge
PVKPVK/SbCl5 doping
1960sOrganic Single
crystals
1980sorganic
Thin films
SonyAMOLED3.8” PDA
Dr. Ching W. TangEastman Kodak
Sir Richard Friend, FRSUniversity of Cambridge
CambridgeChemical Tuning
of PolymerIBM, Bayer
PEDOT:PSS
OLED History
Changhee Lee, SNU, Korea4
디스플레이공학 I2005. 1학기 OLEDC. W. Tang (Kodak): 1st OLED
C. W. Tang and S. A. VanSlyke, Appl. Phys. Lett. 51, 913 (1987)
ITO
Diamine
Alq3
Mg:Ag
Glass
+ ++
-ΦeLight
Φmetal
HOMOAlq3
LUMOAlq3
HOMODiamine
LUMODiamine
ΦITO
Electron
hole
60
40
20
0Li
ght (
arb.
uni
ts)800700600500400
Wavelength (nm)
Alq3
NO
NON
O Al
- -
• High efficiency: 1 % quantum efficiency (electron/photon), 1.5 lm/W luminous efficiency• Low drving voltage: more than 1000 cd/m2 below 10 V
Changhee Lee, SNU, Korea5
디스플레이공학 I2005. 1학기 OLED
PPV
CH
PPV precursor
Cl-
SCH2ClClH2C
+SCl-
S+Cl-
CH2
S+n
n
250oC
Vacuum
MeOH, 50 oC
-OHH+
Dialysis
Synthetic route of PPV
Glass Substrate
ITO
PPV
Al
1.0
0.8
0.6
0.4
0.2
0.0El
ectro
lum
ines
cenc
e (a
rb. u
nit)
2.42.22.01.8
Energy (eV)
120 K
147 K
200 K
235 K
285 K
Cambridge Group: 1st Polymer LED
J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks, K. Mackay, R. H. Friend, P. L. Burns, and A. B. Holmes, Nature 347, 539 (1990).
Changhee Lee, SNU, Korea6
디스플레이공학 I2005. 1학기 OLED
0.20
0.15
0.10
0.05
0.00
EL (a
rb. u
nits
)
800700600500
Wavelength (nm)
N N
N NPt
PtOEP
Princeton/USC Group: Phosphorescent OLED
M. A. Baldo, et al, Nature 395, 151 (1998)
Efficient red EL emission from triplet excitons: ηext ~ 2.2% @ 100 cd/m2
Changhee Lee, SNU, Korea7
디스플레이공학 I2005. 1학기 OLED
Key OLED Patents
• Small Molecule (SMOLED)
C. W. Tang, US Patent 4,356,429 (1982) – Organic electroluminescent cell
S. A. VanSlyke, C. W. Tang, US Patent 4,539,507 (1985) – Organic electroluminescent devices having improved power conversion efficiencies
• Polymer (PLED)
Friend, et al., US Patent 5,247,190 (1993), WO 90/13148 – Electroluminescent devices
Holmes, et al., US patent 5,401,827 (1995), WO 92/03490 – Semiconductive copolymers for use in luminescent devices
• Phosphorescent Molecule (PhOLED)
Thompson, et al., WO 00/70655 – Very high efficiency organic light emitting devices based on electrophosphorescence
Forrest, et al., US Patent 6,515,298 (2003), WO 01/08230 – Intersystem crossing agent for efficient utilization of excitons in organic light emitting devices
Changhee Lee, SNU, Korea8
디스플레이공학 I2005. 1학기 OLED
Updated the data in J. R. Sheats et al., Science 273, 884 (1996).
Blue
White
Red
Green
PDP
AMLCD
CRT
Conventional LEDs
1960 1965 1970 1975 1980 1985 1990 1995 2000 20050.1
1
10
100
Green Yellow
Green 110 lm/W
White OLED20 lm/W
Polyfluorenes
PhosphorescentOLED
Polymers
Molecular Solids
Nitrides
BlueSiC
Organic LEDs
PPV
BlueInGaN
GreenInGaN
Thomas Edison'sfirst bulb
Unfiltered incandescent lamp
Fluorescent
Alq3
Orange-RedAlInGaP/GaP
- OrangeRedAlInGaP/GaAs
RedAlGaAsP/AlGaAs
RedAlGaAsP/GaAs
YellowRedGaAsP:N
GreenGaP:N
Red
GaP:Zn,O Red
GaAs0.6P0.4
Year
Evolution of OLED PerformanceLu
min
ous
Effic
ienc
y (lm
/W)
Changhee Lee, SNU, Korea9
디스플레이공학 I2005. 1학기 OLED
Dendrimers
Overview of OLED Materials
OLED Emitting Materials
Small Molecules
• Quinolates(Kodak)
• DPVBi based (Idemitsu-Kosan)
• Spiro compounds (Covion)
• Phosphorescent (UDC, Opsys)
• PPVs(Philips, CDT, Covion)
• Polyfluorenes(Dow, CDT)
• Spiro bifluorenes(Covion)
Polymers Oligomers Dendrimers
• ADS
• Elam-T
• Opsys
Ref. SRI report
Changhee Lee, SNU, Korea10
디스플레이공학 I2005. 1학기 OLEDHost and Fluorescent Dopant Materials
N
O
N C C N
N
2
DPVBi
Idemitsu Kosan
Alq3Red shift
modifiedGaq3
Perylene
distyrylbiphenylIdemitsu Kosan
Pioneerquinacridone
DPTDPT
rubrenerubrene BTXBTX
ABTX
DCJTBKodak
Kodak
Kodak
B G Y Or R
Host
Dopant
SN
O
OHS
O
OCH3
NH
HN
O
O
NO
NON
O Al
Mitsubishi
Mitsubishi Mitsubishi
Mitsubishi
TDKL
(R)m
2
(R)m
NO
NON
O Al
C H3
H3CC H3
NO
NON
OGa
m-Alq3
Alq-family
Prof. S. K. Kwon (K.N.U.)
Changhee Lee, SNU, Korea11
디스플레이공학 I2005. 1학기 OLED
RedGreen
Dopant
Hole/ExcitonBlockingMaterials
Host
Blue
BCP C60F42
CN-PPV
CBP
mCP
UGH2 TAZ
PVK
FIrpic(CF3ppy)2Ir(pic)
Ir(ppy)3
Ir(ppy)2acac
Ir(mpp)3PtOEP
Btp2Ir(acac)NIr
O
2
ON
F
F
IrN
O O
2
NIr
N
O O
CF3F3C
2
n
O
CN
CHCH2 nN
N N
NNH3C CH3
NN
N
N N
N N
N NPt
NIr
O
2
O
S
FF
F
F
FF F
FFF F
FFF F
F F
FF
F
F
F
F
F FF
FF
F
F
FF
F
F
F
F
FF
FF
FF
NIr
3
Si CH3H3C
NIr
2
H3C
Host and Phosphorescent Dopant Materials
Dr. H. N. Cho (InkTek)
NO
N
O AlO
BAlq
Changhee Lee, SNU, Korea12
디스플레이공학 I2005. 1학기 OLED
BCP, Balq, etc.-Exciton blocking layer
> 1000 Å50 ~ 100 ÅExciton diffusion length
100 %25 %Maximum quantum efficiency
< 10,000 hour10,000 ~ 20,000 hourLifetime
Red: 6~20 cd/AGreen: 17~38 cd/ABlue: ~ 10 cd/A
Red: ~6 cd/AGreen: ~20 cd/ABlue: ~6 cd/A
Luminous efficacy
5 – 15 %0.1 ~ 3 %Dopant concentration
TripletSingletExcited state
CBP, mCPAlq3, ...Host
PhosphorescenceFluorescence
Comparison of fluorescent and phosphorescent OLEDs
Changhee Lee, SNU, Korea13
디스플레이공학 I2005. 1학기 OLEDHole Transporting and Electron Transporting Materials
NN
N
N
NN
CH3
H3C
CH3
NN
O(H3C)3C
NO
NO N
OAl
Hole-transporting materials
Electron-transporting materials
GlassITOHIL
HTL
ETL
Cathode
EML
+
-
N N
CH3
H3C
TPD
α-NPD m-MTDATA
NN
N
TAZ
Alq3PBD
Changhee Lee, SNU, Korea14
디스플레이공학 I2005. 1학기 OLEDHole Injection Materials
GlassITOHIL
HTL
ETL
Cathode
EML
+
-
CuPCCopper Phthalocyanine
PEDOT(Poly(3,4-ethylenedioxythiophene)
Cu
N
N
N
N
n
SO3- SO3
-SO3H SO3H SO3H SO3H
SS
SS
SS
O O
OO
O O
OO OO
n
Andreas Elschner (H.C.Starck), Micro Symposium 2002 (Cologne, 2002. 12. 9)
Changhee Lee, SNU, Korea15
디스플레이공학 I2005. 1학기 OLEDLight Emitting PolymersLight Emitting Polymers
Polyfluorene-based EMLs PPV-based EMLsR1
R2nn
R1 R2
Ar'
Blue to Green or Red Green to redish Orange
Dr. H. N. Cho (InkTek)
Changhee Lee, SNU, Korea16
디스플레이공학 I2005. 1학기 OLED
Phosphorescent Polymers
Blend Type
Main Chain Type
Side Chain Type
Dr. H. N. Cho (InkTek)
Changhee Lee, SNU, Korea17
디스플레이공학 I2005. 1학기 OLEDCurrent status of OLED efficiency and lifetime
SID200425,000 @ 600 nit0.31, 0.6427Green
SID2004-0.39, 0.3938White
White
Blue
Light blue
Green
Red
Light blue
Orange
Red
SID2004-0.14, 0.238
SID200423,0000.30, 0.3412
Organic Electronics 4, 155 (2003)
>15,000 @ 300 nit0.65, 0.3512
PLSID200415,000 @ 300 nit0.61, 0.3822
SID20047,0000.15, 0.155.9
SID200421,0000.17, 0.3012
SID200440,0000.32, 0.6219
EL2004>80,0000.65, 0.355.5
FL
ReferenceHalf-Life (hr)
@ 1000 cd/m2CIE (x,y)
Efficiency (cd/A)
Color
* Fluorescent data : C. Hosokawa, K. Fukuoka, H. Kawamura, T. Sakai, M. Kubota, M. Funahashi, F. Moriwaki and H. Ikeda (Idemitsu Kosan), SID 04 Digest, 780 (2004) Paper 17.1
* Phosphorescent data: Yeh-Jiun Tung, Tan Ngo, Michael Hack, and Julie Brown, Naotaka Koide, Yoshiaki Nagara, Yoshifumi Kato, Hironori Ito, SID 04 Digest, 48 (2004), paper 5.2
Changhee Lee, SNU, Korea18
디스플레이공학 I2005. 1학기 OLED
Methods of Full Color Display Fabrication
RGB method Color conversion method Color filter method
Glass
Anode
HTL
Blue emitting layerETL
Cathode
Red Green Blue
CathodeETL
Anode
Glass
Red Green Blue
Color conversion filter
HTL
White emitting layer
CathodeETL
Anode
Glass
Color filter
Red Green Blue
Changhee Lee, SNU, Korea19
디스플레이공학 I2005. 1학기 OLEDFabrication Methods of OLEDs: small molecules
Vacuum Deposition
Fine Metal Shadow Mask
Substrate
Source
Changhee Lee, SNU, Korea20
디스플레이공학 I2005. 1학기 OLED
Small AreaLow material Usage
Large AreaHigh Material Usage
Point Source Linear Source
Evaporation sources
Changhee Lee, SNU, Korea21
디스플레이공학 I2005. 1학기 OLED
ITO Stripes
Glass Substrate
CathodeSeparator
Cathode Stripes
Organic layer
Changhee Lee, SNU, Korea22
디스플레이공학 I2005. 1학기 OLEDFabrication Methods of OLEDs: small molecules
OVPD
Cooled Carriersubstrate
Organic sources
Heater Showerhead
Evaporation cells
N2 N2
Changhee Lee, SNU, Korea23
디스플레이공학 I2005. 1학기 OLED
Spin Coating
ITO substrate
Solvent Saturated Atmosphere
Spinner Cover
Spinner Motion
Spun Film
Spinner BaseSpinner Bowl
Fabrication Methods of OLEDs: Polymers
Changhee Lee, SNU, Korea24
디스플레이공학 I2005. 1학기 OLED
Process Description (Polymer LED)
Glass with ITO
Structure ITO
Apply Metal-pad
Apply PANI or PEDOT
Structure Polymer & PANI
Apply Polymer
Apply Cathode
Encapsulate
Photolithography
Sputter/Photolith.
Spin Coat
Spin Coat
Laser Ablation
Vacuum Depositon
Adhesive + Lid
Changhee Lee, SNU, Korea25
디스플레이공학 I2005. 1학기 OLED
Ink-jetcartridge
Glass
Transparent electrode: ITO
Polyimide bank
Conducting polymer (PEDOT/PSS)
Red ink
Green ink
Cathode (Al/Ca)
Blue ink
Fabrication Methods of OLEDs: Polymers
Changhee Lee, SNU, Korea26
디스플레이공학 I2005. 1학기 OLED
Fabrication Methods of OLEDs: Molecules, Polymers
glass
Color donor sheetsLaser
LITI Process (small molecules, polymers)Samsung SDI / 3M
Samsung SDI, 17” UXGA (1,600×1,200) AMOLED
Changhee Lee, SNU, Korea27
디스플레이공학 I2005. 1학기 OLED
유리기판
양극
정공수송층 (HTL)발광층 (EML)전자수송층 (ETL)
음극
PMOLED 구조
정공수송층 (HIL)
PMOLED
Changhee Lee, SNU, Korea28
디스플레이공학 I2005. 1학기 OLED
Bottom Emission Top Emission
AMOLED
Al WiringLight
Metal Cathode Transparent Anode
Metal Anode
Translucent Cathode
Transparent Plate
Light
Emissive Layer
Buffer Layer
Emissive Layer
IC
FPC
TFTOLED pixel
TFT backplane
Driver IC
Light Emission
GlassITOHILHTL
ETLCathode
EML
+
-
Changhee Lee, SNU, Korea29
디스플레이공학 I2005. 1학기 OLED
AMOLED TFT-LCD
Backlight
LiquidCrystal
ColorFilter
IC
FPC
IC
FPC
TFTOLED
TFT backplane
Driver IC
Response TimeViewing angleLCD OLED
Display Characteristics: OLED vs LCD
Kodak website
Changhee Lee, SNU, Korea30
디스플레이공학 I2005. 1학기 OLED
Cell Phone Power Consumption Comparison
2” IMT-2000 Cell phone, R:G:B = 3:6:1, 50% polarizer efficiency, 30 % of pixels lit
AMLCDs
Fluorescent AMOLEDs
Polymer AMOLEDs
Phosphorescent AMOLEDs
Luminance (cd/m2)
Pow
er C
onsu
mpt
ion
(mW
)
0 20 40 60 80 100
50
100
200 4 ~ 6 mm
LCD
Backlight
LCD
3 ~ 4 mm
LCD
Backlight
OLED
2.5 ~ 2.8 mm
OLED OLED
Changhee Lee, SNU, Korea31
디스플레이공학 I2005. 1학기 OLED
Comparison of CRT, PDP, LCD, and OLED - TV
Lifetime
Weight/Thickness
Power consumption
Color Fidelity
Image Sticking
Response time
Viewing Angle
Dark condition
Bright conditionContrast
Peak White
Full BlackLuminance
High Resolution
Large Size
OLEDLCDPDPCRTClassification
Excellent Good Fair Need to be improved Dr. C. W. Tang, ICEL-5
Changhee Lee, SNU, Korea32
디스플레이공학 I2005. 1학기 OLED
Segment(area color)
Lighting
Active matrix
Passive matrix
TVHDTV
Notebook PCPC Monitor
DVD PlayerPDADigital Camera
Cell phone, MP3 playerCar stereo
AlphanumericDisplays
LCD backlightGeneral lighting
Dot Matrix
OLED Displays: Applications
Changhee Lee, SNU, Korea33
디스플레이공학 I2005. 1학기 OLED
OLED Displays: Applications
• Monochrome applications* Small monochrome displays for hand-held electronic devices (cell phones, etc.). * Niche applications such as head-mounted displays.
• Multicolor applications* Small displays for hand-held electronic devices (cell phones, PDAs, digital cameras, GPS, etc.). * Car electronics (radios, GPS displays, maps, warning lights, etc.)* Instrument electronics, heads-up instrumentation for aircraft and automobiles.
• Full color application* LCD backlights (white light) * Small full color displays. * Full color, high-resolution, personal communicators* Large displays: TV, monitors* Ultra-lightweight, wall-size television monitors
Changhee Lee, SNU, Korea34
디스플레이공학 I2005. 1학기 OLED
iSuppli, 2004. 9
Worldwide OLED Display Value by Application
Changhee Lee, SNU, Korea35
디스플레이공학 I2005. 1학기 OLED
Samsung LG Electronics
Sanyo-Kodak 2.2” Full-color AMOLED
Sony ‘CLIE’ PDA 3.8” Full-color
AMOLED
PhilipsPioneer
PMOLED
AMOLED
Neosol (Korea) ‘CLIOD’ TMR(TV+portable multimedia player)
2.2” Full-color AMOLED
OLED Products
Changhee Lee, SNU, Korea36
디스플레이공학 I2005. 1학기 OLED
Seiko-Epson40” WXGA (1280x768) tiledAMOLED (Ink-jet printing)
LG Electronics-LG Philips LCD20.1” XGA (1280×800) Poly-Si TFT AMOLED
Samsung Electronics21” WXGA(1280x768) α-Si TFT AMOLED
Samsung SDI17” UXGA (1,600×1,200) Poly-Si TFT AMOLED
Large Area AMOLED
Changhee Lee, SNU, Korea37
디스플레이공학 I2005. 1학기 OLED
$0
$500
$1,000
$1,500
$2,000
$2,500
$3,000
$3,500
2002 2003 2004 2005 2006 2007 2008 2009 2010
AMOLEDPMOLED
Year
Mill
ion D
ola
rs
Ref. iSuppli 2004. 9
OLED Displays: market
Pioneer
35.9%
RiTdisplay15.5%
Philips2.9%
Others4.6%
SamsungSDI
41.1%
Market share (2004)
Changhee Lee, SNU, Korea38
디스플레이공학 I2005. 1학기 OLED
Mobile Phone• 2” QVGA• 1.8” QCIF
Digital Still Camera• 2” Delta
PDA• 3” ~ 4” HVGA or VGA
Entertainment• 4” ~ 6” VGA or WVGA
Car Navigation• 7” VGA or WGA
Notebook• 12” ~ 14”
Desktop PC• 15” ~ 20” SXGA
TV, HDTV• 15” ~ 40” SVGA or WSVGA
Mannfacturing• 2G or 3G manufacturing line
Technology• LTPS-TFT AMOLED• Small Molecule
Mannfacturing• 3G manufacturing line
Technology• LTPS-TFT AMOLED• Small Molecule• Thin film encapsulation
Mannfacturing• 4G ~ 5G manufacturing line
Technology• Super Grain Si-TFT AMOLED• a-Si TFT AMOLED• Small Molecule, Polymer
2004 2005 2006 2007 2008 2009
DisplaySize &
Application
TechnologyRoadmap
OLED Displays: Roadmap
Changhee Lee, SNU, Korea39
디스플레이공학 I2005. 1학기 OLED
OLED Roadmap20032001 2005 2007 2009 2011
1
Gen 1300x400
18”10.4”(x2)
1999
1.45
Gen 2370x470
20”10.4”(x4)
Gen 4730x920
40”17”(x6)
3
Gen 3550x650
26”12.1”(x6)
5.6
Gen 51000x1200
46”17”
(x12)
10
GenGlass
Max panelMain
Product
Lifetime (hour)Lum. Eff. (lm/W)
Drive MethodTFT
EncapEmitterProduct
5,0005
PMLTPS
Metal canSmall Mol.Cell Phone
20,00010
AM TopLTPS/a-Si
Glass, Hybrid S/M, Polymer
Monitor, TV
40,00020
AM TopNon-laser/a-Si
Glass, FilmPolymerHDTV
10,0007
AM BottomLTPS
Glass canSmal Mol.
PDA
Pioneer
Kodak 5.5”Sony 13” IDTech 20” Samsung SDI 17”
KodakLG
Changhee Lee, SNU, Korea40
디스플레이공학 I2005. 1학기 OLED
UDCPioneerDNP
Covion
Flexible OLED Displays
Future DisplayFuture Display
Changhee Lee, SNU, Korea41
디스플레이공학 I2005. 1학기 OLEDFlexible Display: Roll-to-roll coating
Bell Labs/DuPont/Sarnoff
Ref. MRS Fall 2002, Dupont
Roll-up computer
J. M. Shaw, P. F. Seidler, IBM J. Res. & Dev., 45, 3 (2001)
Philips