Scalable AMOLED Technologies for TV Application

Scalable AMOLED Technologies for TV Application T.Tsujimura, S.Mizukoshi, N.Mori, K.Miwa, Y.Maekawa, M.Kohno, K.Onomura, K.Mameno, T.Anjiki, A.Kawakami Kodak Japan Ltd. S.Vanslyke* Eastman Kodak Company

Contents Background  Various technologies for large AMOLED display  Best technology selection from production yield viewpoint  “Scalable” technology set for the quick industry ramp up “Scalable” Mura compensation technology  Global Mura Compensation Scalable OLED technology  White+Color Filter Technology proof for medium to larger AMOLED display Scalable TFT technology Scalable 100% NTSC 8.1”AMOLED display meeting with product specs. Summary

Various technologies for large AMOLED display Shadow mask

Which is the best technology for large AMOLED???

White+Color Filter Laser patterning Laser

re-evaporation  RIST method (Kodak, Sony) Laser transfer  LITI method (3M, Samsung SDI)

PLED, Solution-processed sm-OLED Inkjet,

nozzle coating

This presentation gives you the answer.

Production yield vs. Display size

Upper electrode

Interlayer short Proportional to the electrode area Lower electrode Should be proportional to display size and pixel number TFT Cross-section For example, display size is proportional to the (diagonal length)2 “Defect density” Intralayer short Proportional to wiring length Wiring length is proportional to diagonal size

Electrodes

Defect number surely increases as the (1) Display size increase (2) Resolution increase Wirings plan-view

Production yield simulation 0.4

Point defect probability follows the Poisson equation.

0.35 2-inch 8-inch 14-inch

Probability

0.3 0.25

Yield loss

0.2 0.15 0.1 0.05

(Number of point defect) / (2-inch panel's point defect average)

2" defect criteria=1 (for example)

PSC {k} 

kSC k!

e SC

x50

x45

x40

x35

x30

x25

x20

x15

x10

x5

x0

0

Production yield simulation 32" defect criteria=6 (for example) 0.4

0.35

2-inch 8-inch 14-inch 20-inch 32-inch

Probability

0.3 0.25 0.2 0.15 0.1 0.05

256 times increase of area

(Number of point defect) / (2-inch panel's point defect average)

2" defect criteria=1 (for example)

x300

x250

x200

x150

x100

x50

x0

0

Key for the large display success

Low Defect Density! Minimum cause of defect creation Risky process/structure causes yield loss High performance method does not always lead to the fastest ramp up. For example, Laser patterning vs. White+CF method = Prematured tech vs. Matrured tech

White+CF is the fastest way Defect repair Each TFT in a pixel should have a repair strategy ideally Simple pixel circuit should be chosen for large display

External compensation (Global Mura compensation)

Contents  Background  Various technologies for large AMOLED display  Best technology selection from production yield viewpoint  “Scalable” technology set for the quick industry ramp up “Scalable” Mura compensation technology  Global Mura Compensation “Scalable” OLED technology  White+Color Filter Technology proof for medium to larger AMOLED display “Scalable” TFT technology “Scalable” 100% NTSC 8.1”AMOLED display meeting with product specs. Summary

Kodak’s external compensation GMC Simple pixel circuit External compensation Vth, m correction

Image Processing

Gain

++ +

Data Latch DAC

Driver IC

Offset Output buffer

Correction data stored in Flash Memory FPC

OLED Display

GMC accuracy

Uniformity @ Low Luminance Uniformity @ High Luminance GMC High Current

GMC Low Current 12000

8000 6000

Before R Before G Before B After R After G After B

10000 num ber of dots

10000 num ber of dots

12000

Before R Before G Before B After R After G After B

4000

8000 6000 4000 2000

2000 0

0 0

1000

2000

3000

4000 5000 6000 Current (A.U.)

7000

8000

9000

0

1000

2000

3000

4000 5000 6000 Current (A.U.)

7000

8000

9000

Global Mura Compensation for medium-size product Kodak OLED WIRELESS FRAME Product announced on Sep/17/2008 7.6” AMOLED KODAK PERFECT TOUCH Global Mura compensation 149mm x 209mm x 98mm 644g 800 x 480 pixels 200cd/m2 >30,000:1 contrast ratio Photokina 2008 STAR Award

Successfully shown product-level capability of Global Mura Compensation for mediumsize display

Contents  Background  Various technologies for large AMOLED display  Best technology selection from production yield viewpoint  “Scalable” technology set for the quick industry ramp up “Scalable” Mura compensation technology  Global Mura Compensation “Scalable” OLED technology  White+Color Filter Technology proof for medium to larger AMOLED display “Scalable” TFT technology “Scalable” 100% NTSC 8.1”AMOLED display meeting with product specs. Summary

“W-RGBW method” (RGBW layout with White emission) and “W-RGB method” (RGB layout with White emission) W-RGB method

W-RGBW method

36.5 cd/A

36.5 cd/A

White OLED Color Filter Emission

7.6

19.3

3.2

Eff.example(cd/A)

Absorption in all filters

19.3

3.2

36.5

• White subpixel does not go through color filter and very high efficiency. • Can fully enjoy white’s high efficiency and long lifetime.

0.9 0.8 0.7 0.6

CIE y

7.6

0.5 0.4 0.3

D65

0.2 0.1 0.0 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

CIE x

• Natural image and Television signal are almost unsaturated colors. (World is Gray.)

Probability in DSC Images (based on 13,000 images)

Color histogram in 13000 pictures (Kodak photo library) Most picture can be expressed by Black/White/Gray image + some color addition

Maximum use of white subpixel without sacrificing the image quality. RGBW method Many RGBW method used in LCD industry was increasing luminance, sacrificing the color reproduction Kodak’s RGBW method for OLED  No impact on color reproduction  Maximum white subpixel use

W-RGBW 方式 White OLED

36.5 cd/A

Color Filter Emission Efficiency example(cd/A) 7.6

19.3

3.2

36.5

Kodak’s RGBW algorithm Region-1 RGB method

RGBW method

Red

White

CIE y

Green 0.9 0.8 Region-1 Blue 0.7 Region-2 Region-2 D65 0.6 0.5 RGB method 0.4 Red 0.3 Green 0.2 Blue Region-3 0.1 0.0 0.00.10.20.30.40.50.60.70.80.9 Region-3

CIE x

Green Blue

RGBW method

Red Green White

RGB method

RGBW method

Red

Red

Green

White

Blue

Blue

Kodak’s RGBW 0.9 0.8 Region-1 0.7 Region-2 D65 0.6 0.5 0.4 0.3 0.2 Region-3 0.1 0.0 0.00.10.20.30.40.50.60.70.8

CIE y

Normal RGB method

CIE x

Kodak’s RGBW algorithm Region-1 RGB method

RGBW method

Red

White

CIE y

Green 0.9 0.8 Region-1 Blue 0.7 Region-2 Region-2 D65 0.6 0.5 RGB method 0.4 Red 0.3 Green 0.2 Blue Region-3 0.1 0.0 0.9 Region-3 0.00.10.20.30.40.50.60.70.80.9

CIE x

Green Blue

RGBW method

Red Green White

RGB method

RGBW method

Red

Red

Green

White

Blue

Blue

Kodak’s RGBW 0.9 0.8 Region-1 0.7 Region-2 D65 0.6 0.5 0.4 0.3 0.2 Region-3 0.1 0.0 0.00.10.20.30.40.50.60.70.8

CIE y

Normal RGB method

CIE x

No

impact on color reproduction Pure primary emission for pure colors Maximum use of high efficiency white

Region-1

Normal RGB method

RGB method

RGBW method

Red

White

CIE y

Green 0.9 0.8 Region-1 Blue 0.7 Region-2 Region-2 D65 0.6 0.5 RGB method 0.4 Red 0.3 Green 0.2 Blue Region-3 0.1 0.0 0.00.10.20.30.40.50.60.70.80.9 Region-3

CIE x

Green Blue

RGBW method

Red Green White

RGB method

RGBW method

Red

Red

Green

White

Blue

Blue

Kodak’s RGBW 0.9 0.8 Region-1 0.7 Region-2 D65 0.6 0.5 0.4 0.3 0.2 Region-3 0.1 0.0 0.00.10.20.30.40.50.60.70.8

CIE y

Kodak’s RGBW algorithm

CIE x

Power comparison of “W-RGBW method” and “W-RGB method” with actual product design 2.2“ Diagonal, 100cd/m2, 44% polarizer case

Power [mW]

400

W-RGB

300 200 100

W-RGBW 0 1

2

3

4

Average of 13000 images 180 mW – W-RGBW method 5 6 7 8 9 10 13 34011 mW12 – W-RGB method Picture number Almost half the power with WW-RGBW method!

Performance target for large TV 32-52" HDTV

LCD TV

Plasma TV

OLED Target

Peak luminance(cd/m2)

>500

>300

>500

Viewing angle (Contrast>500)

90-120º

180º

180º

Gamut (NTSCxy%)

100%

100%

102%

Dark contrast

2000:1

2000:1

5000:1

Resolution

HDTV 1080 p

HDTV 1080 p

HDTV 1080 p

T50 (h)

50,000

60,000

50,000

Coexistence of high efficiency and wide color gamut W-RGB method 36.5 cd/A

W-RGBW method White OLED

36.5 cd/A

Color Filter Emission 7.6

19.3

3.2

Efficiency example(cd/A) 7.6

19.3

3.2

36.5

Absorption in all filters

Power consumption is almost depend on White subpixel only.

High-efficiency cool white OLEDs can be achieved using fluorescent emitters 2-stack tandem white OLED structure using Kodak OLED materials: • Green dopant EK-GD403, green host EK-BH109 • Yellow dopant EK-YD3 • Blue dopant EK-BD9, blue host EKBH121 • Electron transport materials EK-ET44, EK-ET902, EK-ET300

Aluminum Cathode Li-doped ETL Green EML Yellow EML HTL P-type layer Li-doped N-type layer Blue EML HTL HIL ITO Anode Substrate

At 1000 nits: • Drive Voltage = 6.2 V • Luminance Efficiency = 36.5 cd/A • Power Efficiency = 18.6 lm/W • External Quantum Efficiency = 15.5% • CIEx,y = (0.28, 0.33), CCT ~ 8500K • Lifetime = 50,000 h

Stack2 (Y-G)

Stack1 (B)

J.Spindler et al, IDRC2008

High-efficiency 3-stack tandem white OLED for improved lifetime Aluminum Cathode Li-doped ETL Green EML Yellow EML HTL P-type layer Li-doped N-type layer Blue EML Yellow EML HTL P-type layer Li-doped N-type layer Blue EML HTL HIL ITO Anode Substrate

Stack3 (Y-G)

Stack2 (Y-B)

Stack1 (B)

At 1000 nits: • Drive Voltage = 9.4 V • Luminance Efficiency = 48.4 cd/A • Power Efficiency = 16.1 lm/W • External Quantum Efficiency = 19.4% • CIEx,y = (0.33, 0.36), CCT ~ 5300K • Lifetime = 75,000 h

Further efficiency improvement by phosphorescence employed for the prototype J.Spindler et al, IDRC2008

Need further improvement for competitiveness!! By means of W-RGBW approach, the power consumption can be reduced to almost half! *M. J. Murdoch et al. , Perfecting the color reproduction of RGBW OLED, proc. ICIS 2006 (2006). However, still W-RGBW method performance is not enough to compete with LCD technology W-RGBW in SID2007

LCD in the market

78% NTSC -

300 cd/m2 @4% window

Peak Luminance >200 cd/m2@Full White Contrast Ratio Color Gamut LTPS OLED

>50,000 100% Non-ELA LTPS TFT White emission + Color Filter

Scalable to larger size and larger substrate with low risk! Combination of Scalable Technologies ONLY as a proof. Non-ELA LTPS + White emission + Color Filter achieving 100%NTSC!

Power consumption difference between W-RGB and WRGBW

W-RGBW in SID2007

Color reproducibility Power consumption

Prototype fabricated

LCD in the market

78% NTSC

100% NTSC

-

1.90W