초저가 유기 면광원 조명 핵심기술 연구초저가 유기 면광원 조명 핵심기술 연구

조 성 민

성균관대학교 화학공학부

2009. 12. 18.

Add-Vision, Inc. (U.S.A.)

Printed P-OLED 제조 공정

Add-Vision Patents1. Screen Printing Light-Emitting Polymer Patterned Devices, US 6,605,483 filed April 2000. 2. Printable Electrode for Light Emitting Polymer Device, US 2003/0153141 A1 filed Dec 2001. 3 S P i t bl El t l i t P l I k US 7 115 216 fil d D 20013. Screen Printable Electroluminescent Polymer Ink, US 7,115,216 filed Dec 2001. 4. Method for Encapsulation of Light Emitting Polymer Devices and Apparatus made by Same,

US 2004/0187999 filed Dec 2002.

Add-Vision, Inc. (U.S.A.)

Low-cost PLED Signage

BarixTM coated barrier flexible substrateBarixTM thin-film encapsulationScreen-printed polymer light emitting inksScreen-printed air-stable cathode metal ink (Ag)

Mitsubishi 155 inch modular OLED TV

SRI International, U.S.A.

Table of contents

(1) OLED lighting : Key issues

(2) Fabrication cost of OLED lightings

(3) Alternative TCO (Transparent Conducting Oxides) technology

(4) How to achieve all solution-processed OLEDs?(4) How to achieve all solution processed OLEDs?

(5) Large-area OLED lighting panels

(6) White PLEDs for OLED lighting

(7) Summary

Recent OLED lighting R&D projects

Light In-Line : Lowering the cost of OLED manufacturing: a German funded research and development project : 3 years from 2009. 7. 1. ( 7 million euro )

Combined OLED technology for large area and low costlightings applications (CombOLED)

: Applied Materials GmbH, Merck KGaA

lightings applications (CombOLED): a European funded research and development project within the 7th Framework Programme

: 3 years from 2008. 1. 1. ( 7 million euro )

OLED100. eu funded under 7th Framework ProgrammePower efficiency : 100 lm/WLifetime : 100,000 hour Size : 100cmⅹ100cmCosts : 100 euro/m2

: 3 years from 2008. 9. 1. ( 12.5 million euro )

Fast2Light : cost-effective, high-throughput, roll-to-roll, large areadeposition processes for fabricating light-emitting polymer-OLED for lighting applications: a European funded research and development project within the 7th Framework Programme : 3 years from 2008. 1. 1.

OLED lighting : KEY issues

(1) Efficiency

“V i t t f l ill i ti ”“Very important for general illumination”

(2) Cost

“Low-cost can create new applications of OLED lightings.”

(3) Lifetime(3) Lifetime

“Enough for general illumination when exceeds 10,000 hours”

※ Cost reduction should be the first goal for OLED technology※ Cost reduction should be the first goal for OLED technology

to create or enter new solid-state lightings (SSL) markets.

SMOLED versus PLED

n type ETL (n)

Cathode

Cathode

SMOLED PLED

n-type ETL (n)

Hole BL

Emissive Layer (i) Interlayer

Cathode

Emissive Layer

p type HTL (p)

Electron BL

Emissive Layer (i)

Anode

HIL

Interlayer

Anode

p-type HTL (p) Anode

(1) Highest efficiency : 102 lm/W @ 1,000

cd/m2 (Universal Display Corporation)

(1) Highest efficiency : 20-30 lm/W

@ 1,000 cd/m2 (GE, CDT)

(2) High-cost fabrication process

(3) Complex structure (more than 10 layers)

(4) Long lifetime

(2) Low-cost fabrication process

(3) Simple structure (less than 4 layers)

(4) Short lifetime(4) Long lifetime (4) Short lifetime

Areas of impact on OLED lightings

The biggest impact on OLED lightings : Low cost substrate selectionScalable manufacturing processLow cost manufacturing process

Voltage

g p

EfficiencyScalability

fil LifetimeLow cost film deposition

Critical problems for OLED lightings

Metric 2008 2010 2012 2015

Efficacy – Lab (lm/W) 58 99 150 150

Efficacy – Commercial (lm/W)

N/A 44 76 150

D i P i ($/kl ) N/A 72 27 10Device Price ($/klm) N/A 72 27 10

Device Price ($/m2) N/A 216 80 30

Device Life –

Critical Problem

Device Life Commercial Product

(1,000 hours)N/A 11 25 50

Source : OLED Technical Committee, Fall 2008Source : OLED Technical Committee, Fall 2008

Fluorescent tube : 60 lm/W ; < 1 $/klm ; < 6 $/m2 ; 10,000 hours

Incandescent bulb : 17 lm/W ; < 1 $/klm ; < 6 $/m2 ; 750 hours

Substrate Cost (current) : AMOLED glass : ~ $50/m2

PDP glass : ~ $30/m2

PMLCD : $10/m2PMLCD : ~ $10/m2

Window glass : ~ $ 4/m2

Cost estimation of OLED lightings

Key assumptions GEN 4 730ⅹ920 GEN6 1500ⅹ1800 WET (R to R)

Organic deposition utilization (%) 50 70 70

TACT time (min) 3 2 < 2TACT time (min) 3 2 < 2

Yielded output per month (m2) 5,667 55,891

Equipment costs ($) $40M $100M $10M

Cost ($/m2)

Substrate 10 8

Anode/Cathode 10 5(BOM : 30%)

Organics 28 16

Encapsulation 10 8

Labor 41 5

Equipment 100 27 2

Yield 35 8

Outcoupling 11 9

(30%)(1/10)

Total Yielded Cost ($) 245 86

$Total Yielded Cost per klm ($/klm) 40 13 4

(1/3)

UDC G.E.

Issues on anode/cathode for OLED lightings

Anode Cathode

● Usually transparent ● Usually opaque- ITO - Ba- AZO (ZnO:Al) - Ca

Very thin metal Mg/Ag- Very thin metal - Mg/Ag- CNT or Graphene - Al/LiF

● High work function ● Low work function~ 5 eV ~ 3 eV

● Low refractive index ● Reactive< 2 0 - Easily oxidized< 2.0 - Easily oxidized

● Low sheet resistance ● Must be deposited onto organics< 1 Ω/square !! - Careful vapor deposition- Probably need metal grid - Direct printing of inks

- Lamination● Low cost - Transfer

< $5/m2< $5/m

Solution-processed alternative for ITO - AZO

mist

substrateN2Heated substrate holder

Ultrasonic generator

Moving stage

LME price ($/ton)

1. Scalable process to large area

2 L t

p ($/ )Zn 1,895Al 1,830In 610,000

2. Low-cost non-vacuum process

3. Roll-to-roll process capabilitySn 14,900Mg 3,000Ag 570,000Au 35,350,000

(2009.9.11)

AZO (ZnO:Al) growth – Arrhenius plot

4.0 Activation energy for the growth reaction : 34 kJ/mol·K

3.5

min

))

3.0e (n

m/m

Slope = -4,200

2.5

owth

Rat

2.0

Film

Gro

0.0016 0.0018 0.0020 0.00221.5

ln(F

1/T (K-1)

Properties of AZO (ZnO:Al) thin films

100 1021 20

Hexagonal Wurtzite

10-1 15-3)

Hexagonal Wurtzite crystal structure

(A.U

.)

10

1020

15

hm-c

m)

atio

n (c

m-

2 /Vse

c)

350oC

nten

sity

10-2

1019

10

sist

ivity

(O

Con

cent

ra

bilit

y (c

m2

300oC

I

10-3 5Res

Car

rier C

Mob

250oC

200oC

20 30 40 50 60 70 800 2 4 6 8 10 12

10-4 1018 0

Al concentration (wt %) 2 th t

200oC

Al concentration (wt.%) 2 theta

Properties of AZO (ZnO:Al) thin films

80

100

80

100

60

tanc

e (%

)

60

80

Al-doped ZnO (2.5 % doping)Growth Temperatureta

nce

(%)

20

40Al doping concentrations(Growth Temp. : 300oC) 0% 2.5% 5%

Tran

smitt

20

40 Growth Temperature 200oC 250oC 300oC 350oC

Tran

smitt

300 400 500 600 700 8000

7.5% bare ITO

Wavelength (nm)300 400 500 600 700 8000

Bare ITO

Wavelength (nm)

Properties of AZO (ZnO:Al) thin films

CharacteristicsCommercial Asahi U-type

Ultrasonic-mistdeposited AZOCharacteristics

ITO FTO (SnO2:F)deposited AZO

(ZnO:Al)

Average 82% 79 5% 80%

transmittance82% 79.5% 80%

Optical bandgap 3.5 eV 3.9-4.2 eV 3.3 eV

L thi k 200 900 1 200Layer thickness 200 nm 900 nm 1,200 nm

Sheet resistance 5 Ω/square 13 Ω/square 10 Ω/square

Resistivity 0 25 mΩcm 1 2 mΩcm 0 9 mΩcmResistivity 0.25 mΩcm 1.2 mΩcm 0.9 mΩcm

Roughness 1.0 nm 34.7±5.2 nm 25.6 nm

Hall mobility 55 cm2/Vsec 38 cm2/Vsec 18 cm2/Vsec

Deposition temp. 170oC 350oC 300oC

Growth Technique Vacuum sputtering APCVD (gas) UMD (solution)

Structure for Solution-Processed OLEDs

For “All solution-processed OLEDs”, - Polymer OLEDs

- Removal of an electron-injection layer such as LiF

- Solution process for the formation of metal electrodes

Conventional Single-Layer OLED Salt-doped P-i-N Single-Layer OLED

Metal Cathode

Bu4N+1 nm LiF

Metal Cathode

PVK-based emitting layer

BF -

PVK-based emitting layer

ITO Glass

PEDOT:PSS

BF4

ITO Glass

PEDOT:PSS

Electrical Annealing

Salt-doped P-i-N PolymerOLED4

1.0x104

1.2x104

1.4x104/m

2 )

0.3 wt.% Bu4NBF4 salt doping No salt doping with 1nm LiF Salt doping with 1nm LiF Salt doping without LiF 1.2x104

1.4x104

1.6x104

/m2 )

0.3 wt.% Bu4NBF4 salt doping doped but not treated 30 seconds at 7 V 30 seconds at 10 V30 seconds at 11 V

6.0x103

8.0x103

umin

ance

(C

d/

(A) (B) (C) 6.0x103

8.0x103

1.0x104

Lum

inan

ce (

Cd undoped with 1nm LiF

0 2 4 6 8 10 12 14 16 18 20 220.0

2.0x103

4.0x103Lu

0 2 4 6 8 10 12 14 16 18 20 220.0

2.0x103

4.0x103

L

0 2 4 6 8 10 12 14 16 18 20 22

Voltage (V)

700

800

0.3 wt.% Bu4NBF4 salt doping No salt doping with 1nm LiF

0 2 4 6 8 10 12 14 16 18 20 22

Voltage (V)

1.8x104

2.1x104

Bu4NBF4 salt doping wt.%annealed for 60 seconds at 10 V

400

500

600

p g Salt doping with 1nm LiF Salt doping without LiF

nsity(m

A/c

m2 )

(A) (B) (C)

1.2x104

1.5x104

ance

(C

d/m

2 )

annealed for 60 seconds at 10 V 0.6 wt.% 0.9 wt.% 1.2 wt.% 1.5 wt.% undoped with 1nm LiF

100

200

300

Cur

rent

den

Inflection point

3.0x103

6.0x103

9.0x103

Lum

ina

0 2 4 6 8 10 12 14 16 18 20 220

Voltage (V)0 3 6 9 12 15 18

0.0

Voltage(V)

Salt-doped P-i-N Polymer OLED60000

60000

40000

50000

60000

Salt activation time at 13V 0 sec. 10 sec. 30 sec.

50 sec.d/m

2 )

40000

50000

60000

d/m

2 )

Salt activation 13 V - 30 sec. 15 V - 30 sec. 17 V - 30 sec.18 V 30 sec

20000

30000

50 sec. 70 sec. 90 sec. 110 sec. 130 sec.

Lum

inan

ce (c

d

20000

30000

Lum

inan

ce (c

d 18 V - 30 sec. 19 V - 30 sec.

10 15 20 25 300

10000

5 10 15 20 25 300

10000

500

600

after salt annealingft 1 h

6 8 10 12 14 16 18

10450000

60000

Salt activation time at 13 V0 sec. with LiF

10 15 20 25 30

Voltage (V)5 10 15 20 25 30

Voltage (V)

300

400

500

nce

(cd/

m2 )

sity

(mA

/cm

2 ) after 1 hr after 24 hr

103

10

30000

40000

nanc

e (c

d/m

2 )

0 sec. with LiF 30 sec. with LiF 60 sec. with LiF 90 sec. with LiF 90 sec. without LiF

100

200 Lum

inan

Cur

rent

den

s

10210000

20000

Lum

in

6 8 10 12 14 16 180

Voltage (V)5 10 15 20 25 30

0

Voltage (V)

Salt-doped P-i-N Polymer OLED

25000

30000

35000

400

500

2 ) /cm

2 )

Salt doping concentrationSalt activation voltage Salt activation time

: 0.6 wt.%: 13 V: 10 sec.

12000

16000

100

120

2 )

Conventional device with LiF layerNo salt doping

/cm

2 )

10000

15000

20000

200

300

min

ance

(cd

/m2

nt d

ensi

ty (

mA

/

8000

40

60

80

min

ance

(cd/

m2

nt D

ensi

ty (m

A/

10 15 20 25 300

5000

10000

0

100

Lum

Cur

ren

10 15 20 250

4000

0

20

40

Lum

Cur

ren

Voltage (V)

50000

60000

400

Salt doping concentrationSalt activation voltage S lt ti ti ti

: 0.6 wt.%: 13 V110

Voltage (V)

60000

75000

500

600

Salt-doped device with LiF layerSalt doping concentration : 0 6 wt %

30000

40000

200

300

nce (c

d/m

2 )

nsity

(m

A/c

m2 )Salt activation time : 110 sec.

45000

60000

300

400

nce

(cd/

m2 )

Salt doping concentration : 0.6 wt.%Salt activation voltage : 13 VSalt activation time : 90 sec.

nsity

(mA

/cm

2 )

10000

20000

100

200

Lum

inan

Cur

rent

den

15000

30000

100

200Lu

min

an

Cur

rent

Den

10 15 20 250 0

Voltage (V)10 15 20 25 30

0 0

Voltage (V)

Salt-doped P-i-N Polymer OLED

60000

70000

10 cd/A

15 cd/A

0 sec. 10 sec. 30 sec.

50 sec

20 cd/A50000

60000

Salt activation time at 13 V 60 sec. with LiF 90 sec. without LiF

N lt d i ith LiF

10 cd/A

30000

40000

50000

nce (c

d/m

2 )

50 sec. 70 sec. 90 sec. 110 sec.

30000

40000

nce (c

d/m

2 )

No salt doping with LiF

10000

20000

300005 cd/A

Lum

inan

Salt activation at 13 V10000

20000

Lum

inan

0 1000 2000 3000 4000 5000 6000 70000

Current density (A/m2)

0 1000 2000 3000 4000 5000 60000

Current density (A/m2)

With the doping of an organic salt (Bu4NBF4) into polymer OLEDs, - balance of electrons and holes in OLEDs

- comparable performance with conventional OLEDs with LiF

- stable OLEDs up to much higher luminance

- similar lifetime to conventional OLEDs

Salt-doped P-i-N Polymer OLED - Fabrication

For “vacuum-free fabrication of polymer OLEDs”, - Transfer process of metal electrode

- Scalable to large area

Emission Layer(PVK PBD TPD Ir(ppy) salt)

Emission Layer(PVK PBD TPD Ir(ppy) salt)

Al

PEDOT:PSS

(PVK, PBD, TPD, Ir(ppy)3,salt)

PEDOT:PSS

(PVK, PBD, TPD, Ir(ppy)3,salt)

ITO ITO

Salt-doped P-i-N Polymer OLED - Fabrication

Salt-doped P-i-N Polymer OLED - Fabrication

500

100C, 5min150C 5min

20000

100C, 5min150C 5 i

300

400150C, 5min 170C, 5min 200C, 5min

mA

/cm

2 ) 15000

150C, 5min 170C, 5min 200C, 5min

d/m

2 )

mA

/m2 )

Cd/m

2 )

Evaporated Evaporated C th d

200

rren

t den

sity

(m

5000

10000

Lum

inan

ce(c

d

ent

den

sity

(

um

inan

ce (

CpCathode Cathode Transferred

Cathode

0 5 10 15 20 250

100Cu

0 5 10 15 20 250

5000

Curr

e LTransferred Cathode

※ Delayed turn-on voltage & limited luminance of cathode-transferred

0 5 10 15 20 25

Voltage(V) Voltage(V)Voltage (V) Voltage (V)

y gdevices seem to be responsible to the native oxide of aluminum cathode.

Salt-doped P-i-N Polymer OLED - Fabrication

For “vacuum-free fabrication of multi-layer polymer OLEDs”, - Transfer process of metal electrode with ETL

Scalable to large area- Scalable to large area

Al

Emission Layer(PVK PBD TPD Ir(ppy) salt)

Emission Layer(PVK PBD TPD Ir(ppy) salt)

Al

ETL + electron injection promoter

PEDOT:PSS

(PVK, PBD, TPD, Ir(ppy)3,salt)

PEDOT:PSS

(PVK, PBD, TPD, Ir(ppy)3,salt)

ITO ITO

Inverted Salt-doped P-i-N Polymer OLED

For “full solution-processed polymer OLEDs”, - Direct printing of metal electrode from metal pastep g p

- Scalable to large area

Al or Ag

paste printing of metals

Emission Layer(PVK, PBD, TPD, Ir(ppy)3,salt)

PEDOT:PSSEmission Layer

(PVK, PBD, TPD, Ir(ppy)3,salt)

PEDOT:PSS

ITO

Mist deposited ZnO

ITO

Mist deposited ZnO

ITO ITO

Inverted Salt-doped P-i-N Polymer OLED

2.2

2.5

3.0

2.3PVK

--

+++

ITO (4.7)

ITO (4.7)

5 8

ITO (4.7)

Z O

4.4PEDOT(5.0)

Al (4.3)

6.05.6 5.5

--------

+++++++

PEDOT(5.0)

Al (4.3)

PEDOT(5.0)

Al (4.3)

5.8ZnO

7.6

Ir(ppy)3PBD TPD

V- +

V- +

ITO (4 7)

VV

ITO

------

++++++++

PEDOT(5 0)

Al (4.3)

(4.7)

ZnO

4.4

PEDOTAl (4.3)

(4.7)

ZnO

4.4

---

++

(5.0)

7.6

(5.0)

7.6

V- +V- +

Inverted Salt-doped P-i-N Polymer OLED

PEDOT:PSS

900 ZnO layer ; salt doping No ZnO layer ; salt doping ZnO layer ; No salt doping

3 6 9 12 15 18 21 24 27

10000

ITO

ZnO

Emitting layerPEDOT:PSS

600

nce

(cd/

/m2 )

esity

(mA

/cm

2 )

1000

3 6 9 12 15 18

Glass300

Lum

inan

Cur

rent

de

100

900

)

Conventional device with LiF (Fig.1 (b)) Salt-doped device (Fig.1 (c)) Inverted salt-doped device with ZnO (Fig.1 (a))

3 6 9 12 15 18

100003 6 9 12 15 18 21 24 27

0

Voltage (V)

600

ce (c

d/m

2 )

esity

(mA

/cm

2 )1000

300

Lum

inan

c

Cur

rent

de

100

3 6 9 12 15 180

Voltage (V)RMS 6.7 nm

Screen printing : Equipment

Pressure GuageGuage

Mask Align

S lift

Controller

Screen-lift

Controller

Vision CameraSqueeze & Scraper

Mask Holder

Screen printing : pixels

1ｘ2 mm2 pixels

1 mm

23.5 m

23 5

mm

23.5 mm

Large-Area OLED panel : Uniformity

Organic Curing(min) Thickness(nm) α-step images

Screen printing : Uniformity higher than 90% over 10 cm ⅹ 10cm area

g g p g

1 30 77

2 30 711

3 30 662 5 3

4 30 764

5 30 775 30 77

Large-Area OLED panel ( Structure I )

Al PVPPVP E i i l E i i l

PVP

150×150 100×100

PVP Bank

PVPBank Emissive layer Emissive layer

ITO

PEDOT:PSS

Gl

PEDOT:PSSCu Cu

Bank

Cu

Glass

Electrolessly depositedScreen printing of

Large area OLED panelElectrolessly-deposited Cu grids

p gPEDOT:PSS, PVP, and

emissive layer

Large-area OLED panel

Large-Area OLED panel ( Structure I )

screen printed PMMA pattern

Sn, Pd seeds for Cu plating

glass

ITO screen-printed PMMA pattern

screen-printed PMMA over-layer

electroless-plated Cu lines

Large-Area OLED panel ( Structure I )

Large-Area OLED panel ( Structure I )

Large-Area OLED panel ( Structure II )

(1) ITO wet etching using screen printed PMMA mask

(2) Screen printing of PEDOT:PSS and emissive layer( ) p g y

(3) Evaporation or transfer of aluminum metal cathode

(1) (2) (3)(1) (2) (3)

ITOPEDOT:PSS and

AlITO emissive layers Al

Large-Area OLED panel ( Structure II )

White OLEDs (single layer)

Metal Cathode (Al)

LiF

PVK-based white emitting layer

PVK ; OXD-7

Firpic (B) ; Ir(mppy)3 (G) ; Ir(piq)2 (R)

ITO Glass

PEDOT:PSS + polysilics acid (PSA)

ITO Glass

White OLEDs (single layer) : Efficiency

D i C iti CIE 1931 coordinates Max. brightness Max. current ffi i CCT

Table 1. Device performance of the white PLEDs doped with red, green and blue phosphorescent dyes.

Device Composition CIE 1931 coordinates at 1000 cd/m2

Max. brightness [cd/m2] efficiency

[cd/A]

CCT[K]

A[a] 100:1[c] 0.232 0.398 1,780 1.93 9,500A 00 0 3 0 398 , 80 93 9,500

B[a] 100:2[c] 0.304 0.379 1,860 1.21 7,100

C[a] 100:3[c] 0.374 0.375 1,300 1.7 4,100

D[b] 50:0.1:1.2[d] 0.357 0.360 3,500 4.3 4,500

E[b] 50:0.1:1.5[d] 0.405 0.341 4,800 4.7 3,200

F[b] 50:1 :1[d] 0.301 0.468 12,200 13.7 5,550

[a] Doubly-doped devices. [b] Triply-doped devices. [c] FIrpic:Ir(piq)2 ratio; FIrpic is fixed at 10 wt% of the active layer blend. [d] FIrpic:Ir(ppy)3:Ir(piq)2 ratio; FIrpic is fixed at 10 wt % of the active layer blend.

White OLEDs : PSA incorporation

Table 2. Effects of PSA nanodots with different concentrations in hole injection layer on the EL performance of the white PLEDs

DevicePSA concentration (wt%

Turn on voltage CIE 1931 coordinates

1000 d/ 2

Max. brightness

Max. current efficiency

Current density at

1000Device tration (wt% of PEDOT)

voltage [V] at 1000 cd/m2 brightness

[cd/m2]efficiency [cd/A], [V]

1000 cd/m2

[mA/cm2]

1 0 6.3 0.332 0.468 12230 13.7, 13.1 10.41 0 6 3 0 33 0 68 30 3 , 3 0

2 0.75% 6 0.325 0.479 11600 15.2, 10.8 8.0

3 1 50% 5 2 0 327 0 496 15000 22 9 10 3 6 13 1.50% 5.2 0.327 0.496 15000 22.9, 10.3 6.1

4 3% 4.8 0.362 0.51 15300 21.3, 9.6 5.7

5 5% 5 3 0 373 0 461 7450 20 4 11 6 5 45 5% 5.3 0.373 0.461 7450 20.4, 11.6 5.4

6 10% 5.3 0.325 0.507 3700 30.3, 11.8 4.7

White OLEDs with interlayer

Metal Cathode (Al)

LiF

PVK-based white emitting layer

PVK ; OXD-7 ; TCTA

Firpic (B) ; Ir(mppy)3 (G) ; Ir(piq)2 (R)

PEDOT:PSS

Interlayer (TCTA)

ITO Glass

White OLEDs with interlayer

2.2

2.82.82.72.6

3.12.42.42.62.6

Interlayer Emissive layer Triplet energy (eV)

2.7FIrpic

2 4

5 05.2

PED

OT

TCTA

TCTA

TPD

α-N

PD

FIrp

ic

Ir(m

ppy)

3

Ir(p

iq) 2

LiF/

Al

OXD

-7

2.8TCTA

2.34

2.4Ir(mppy)3

5.8

6.5

5.05.1

5.75.45.4

5.95.9PVK

TPD2.29

α-NPD

2.0Ir(piq)3

350

400 No TCTA, α-NPD, TPD 5% TCTA 5% α-NPD5% TCTA + 5% NPD

0 5 10 15 20 25

104

20

25

No TCTA, α-NPD, TPD 5% TCTA 5% α-NPD5% TCTA + 5% α NPD

1,700 cd/m2

200

250

3005% TCTA + 5% α-NPD 5% TPD 5% TCTA + 5% TPD

nsity

(mA

/cm

2 )

102

103

ance

(cd/

m2 )

15

5% TCTA + 5% α-NPD 5% TPD 5% TCTA + 5% TPD

ffici

ency

(cd/

A) 19.7 cd/A

50

100

150

Cur

rent

de

101

Lum

ina

5

10

Cur

rent

Ef

13 V

0 5 10 15 20 250

Voltage (V)

100

5 10 15 20 250

Voltage (V)

White OLEDs with interlayer

300

2 )

0% TCTA 3% TCTA 5% TCTA

7% TCTA

5 10 15 20 25

104 20

24

A) 19.8 cd/A

1,600 cd/m2

200

min

ance

(cd/

m2 )

dens

ity (m

A/c

m2 7% TCTA

10% TCTA

103 12

16

t effi

cien

cy (c

d/A

0

100

Lu

Cur

rent

102

0

4

8

Cur

ren 0% TCTA

3% TCTA 5% TCTA 7% TCTA 10% TCTA12.3 V

5 10 15 20 250

Voltage (V)6 8 10 12 14 16 18 20 22

0

Voltage (V)

400 Undoped emissive layer Undoped emissive layer with interlayerDoped emissive layer

5 10 15 20 2525

1,800 cd/m2

200

300

sity

(mA

/cm

2 )

e (c

d/m

2 )

Doped emissive layer Doped emissive layer with interlayer

104

15

20

ncy

(cd/

A) 20.5 cd/A

100

200

Cur

rent

den

s

Lum

inan

ce

103

5

10

Undoped emissive layerUndoped emissive layer with interlayer

Cur

rent

Effi

cien

5 10 15 20 250

Voltage (V)

102

6 8 10 12 14 16 18 200

Undoped emissive layer with interlayer Doped emissive layer Doped emissive layer with interlayer

Voltage (V)

11.5 V

Summary

(1) For low-cost OLED lightings, low-cost TCO substrates is necessary.

(2) Full vacuum-free fabrication of white OLEDs is possible by metal(2) Full vacuum free fabrication of white OLEDs is possible by metal

transfer technique.

(3) Full solution-processed OLED lightings could be realized by utilizing

the inverted structure of OLEDs.

(4) Large-area OLED lighting panel can be realized using solution

processes such as screen or gravure printings.

(5) Power efficiency of white polymer OLEDs needs to be improved.

( World highest : 25 lm/W @ 1,000 cd/m2 )

( O l b t hi h t 15 l /W @ 1 000 d/ 2 )( Our laboratory highest : 15 lm/W @ 1,000 cd/m2 )