Active Matrix Full Color OLED...

© eMagin CorporationChina FPD 03-17-2011

Amalkumar P. Ghosh, Tariq A. Ali, Ilyas Khayrullin, Olivier F. Prache, Ihor Wacyk

eMagin Corporation2070 Route 52, Hopewell Junction, NY 12533

Active Matrix Full Color OLED Microdisplays


� Introduction

� Technology

� Process Overview

� Performance & results

� Summary

� Acknowledgement

Outline


eMagin

� Located in Hopewell Junction, New York

� OLED development started in 1997

� First Active Matrix OLED Microdisplay shipped in 2002

� Currently the only company in full production of Active Matrix OLED microdisplays

eMagin

Corporation


Introduction

eMagin microdisplays:

� Typically need a lens to view

� Are primarily for near-to-the-eye applications

Virtual image ~ 105 inches diagonal at 12 feet


Applications

MedicalMedicalConsumer

Industrial Military


Post processing at eMagin

eMagin’s Technology

200 mm single crystal silicon wafers

CMOS drive circuitry from

foundry

High Tgfluorescent materials

Top Emitter Top Emitter Top Emitter Top Emitter

White OLED White OLED White OLED White OLED

Thin Film Seal Thin Film Seal Thin Film Seal Thin Film Seal

Color FiltersColor FiltersColor FiltersColor Filters


eMagin’s Display PlatformsSXGA 1280 x 1024

• 0.77 inch diagonal

• 12.0 µm pixel pitch

• 4.0 µm sub-pixel pitch

SVGA+ 852 x 600




WUXGA 1920 x 1200




Active

Area

22.9 mm

15.5 mm

16.4 mm 12.43 mm

WUXGA US Quarter

17.5 mmActive

Area

26.4 mm

18.74 mm

11.77 mm

4.72 mm

Encapsulant

Cover GlassSilicon Die

Connector

Carrier PCB4.72 mm

SXGA US Quarter

Active

Area

19.8 mm

12.8 mm

15.2 mm 9 mm

5.1 mm

SVGA US Quarter


Back Plane Layout

SXGA 1280 x1024

0.77” diagonal

• Peripheral drive circuitry is on the silicon

• Self contained and highly integrated display

WUXGA 1920 x1200

0.86” diagonal

LV

DS

IO

Tim

ing

Ra

mp

DA

CR

am

p B

uff

er

Ram

p B

uff

er

COLUMN DECODERS & SWITCHES

RO

W D

EC

OD

ER

S

TIM

ING

DA

CS

EN

SO

RS

DC

-DC

SE

RIA

L IO



RO

W D

EC

OD

ER

S

TIM

ING

DA

CS

EN

SO

RS

DC

-DC

SE

RIA

L IO


Sub-pixel dimensions: 4 µµµµm x 11 µµµµm Sub-pixel dimensions: 2.45 µµµµm x 8.5µµµµm


Highlights of Drive Circuit

� Current driven architecture: SVGA+

• Simpler gamma control but limited to ≥≥≥≥ 15x15um square pixel

� Voltage driven architecture (SXGA & WUXGA)

• Allows for a smaller pixel size

• Provides a better storage capacitor to pixel size ratio

• Improved pixel-to-pixel uniformity

• RGB digital interface – feature for our latest architecture

• On board low power DAC

• Built in features

• Gamma correction

• Luminance regulation over wide temp range

• Row and column addressing circuitry

eMagin’s OLED Microdisplays have very low power consumption – 75% less than a comparable LCD microdisplay


Microdisplay Specifications

Parameter SVGA+ SXGA WUXGA Format (pixels) 852(x3) x 600 1280(x3) x 1024 1920(x3) x 1200

Color Pixel Aspect Ratio

15µm sq. color group 12µm sq. color group 9.6µm sq. color group

Color Pixel Arrangement

R, G, B vertical stripe R, G, B vertical stripe R, G, B vertical stripe

Display Size 0.61” diagonal 0.77” diagonal 0.86” diagonal

Gray Levels 256 per primary color 256 per primary color 256 per primary color

Operating Ambient Temp.

-45ºC to +70ºC -45ºC to +70ºC -45ºC to +70ºC

Storage Temp. -55ºC to +90ºC -55ºC to +90ºC -55ºC to +90ºC

Sub-pixel Width x Height (active area)

3.5 µm x 13.5 µm 4 µm x 11 µm 2.45 µm x 8.5 µm

Fill Factor 63 % 69 % 71 %


Device Structure of OLED on Silicon

Reflective Anode

ETL

Doped EML (Orange)

Doped EML (Blue-Green)

HIL

Transparent Cathode

HTL

Reflective Anode

ETL

Doped EML (Orange)

Doped EML (Blue-Green)

HIL

Transparent Cathode

HTL


Schematic of Color OLED Microdisplay

Organic

Layers

Reflective Anode

ETL (150-250 Å)

Orange-Red Emitter

Blue-Green Emitter

HIL (150-250 Å)

Semitransparent Cathode

HTL (150-250 Å)

White Light

CMOS Si Substrate

_

+

Seal Layer

Color

FiltersR G B

Organic

Layers

Reflective Anode

ETL (150-250 Å)

Orange-Red Emitter

Blue-Green Emitter

HIL (150-250 Å)

Semitransparent Cathode

HTL (150-250 Å)

White Light

CMOS Si Substrate

_

+

Seal Layer

Color

FiltersR G B

• High Tg materials

• Two layer white structure

• High reflective metal anode

• Thin film seal

• Color filters directly on top of seal


eMagin’s Microcavity Modeling Software

Features:� Monte Carlo simulation up to 30 layer stack OLED� Simultaneous independent thickness variation for two individual

layers – 2D Mapping of any given parameter vs. two thicknesses� Viewing angle variation� Multi-dopant capability in individual emission layers� Exciton diffusion length variation� Dopant concentration variation

Output:� Spectra� 1931 CIEx and CIEy� 1976 CIEu’ and CIEv’� Luminance� Out-coupling efficiency


Example of Modeling

0.0

0.2

0.4

0.6

0.8

1.0

1.2

380 430 480 530 580 630 680 730 780

Wavelength (nm)

No

rma

lize

d I

nte

nsit

y (

a.u

.)eMagin XL-OLED

Simulation

Experiment

Simulation

0.0

0.2

0.4

0.6

0.8

1.0

1.2

380 430 480 530 580 630 680 730 780

Wavelength (nm)

No

rma

lize

d I

nte

nsit

y (

a.u

.)eMagin XL-OLED

Simulation

Experiment

Simulation


Color Pixel Layout

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B R G B R G B R G B R G B R G B

R G B

R G B

R G B

R G B

R G B

R G B

R G B

ROW 0

ROW 1

ROW 2

ROW 1033

ROW 1034

ROW 1035

COLUMN #: 0 1 2 1289 1290 1291

6 31292

11

03

61


OLED Micro-display Fabrication

Si wafer

from foundry

Deposit and

pattern anode

OLED

deposition

Thin film seal

Color filter

processing

Cover glass

attach

Microdisplay

singulation

Die attach to

board

Wire bond, test

& inspect


Typical LIV for SXGA

eMagin OLED LIV Characteristic (25

oC)

0.0001

0.001

0.01

0.1

1

10

100

0 1 2 3 4 5 6 7

Vbias

Cu

rren

t D

en

sit

y (

mA

/cm

2)

0.01

0.1

1

10

100

1000

10000

Lu

min

an

ce (

cd

/m2)

3V

Video Mode

White Level

Black Level


Typical CIE Color Coordinates for SXGA

0.120.15Blue

0.530.26Green

0.350.63Red

0.370.30White

CIEyCIExColor


Temperature Compensation

Luminance vs. Temperature

0

0.5

1

1.5

2

-60 -40 -20 0 20 40 60 80

Temperature (oC)

No

rmalize

d L

um

inan

ce

SXGA

SVGA


OLED I-V Compensation with Temperature

0

5

10

15

20

25

30

0 1 2 3 4 5 6 7 8 9 10

Bias Voltage

Cu

rre

nt

De

ns

ity

(m

A/c

m2)

80oC 20oC -40oCPixel Operating

Window at 20oC

� Many applications require a wide temperature range

� Back plane is designed to provide the voltages for this wide operating temperature range


Temperature Dependence of Contrast

SXGA Contrast vs. Temperature (100 cd/m2)

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

-60 -40 -20 0 20 40 60 80

Temperature (oC)

Co

ntr

as

t R

ati

o


CIE Coordinates versus Gray Level

SXGA: CIE vs. Gray Level (Lmax = 310 cd/m

2)

0.3

0.32

0.34

0.36

0.38

0.4

0 50 100 150 200 250

Gray Level

CIE

CIE-Y

CIE-X


Angular Dependence of Luminance

SXGA - Rotation About Axis (R3BLP) - Color display

0

0.2

0.4

0.6

0.8

1

-30 -20 -10 0 10 20 30

Angle (Degree)

No

rmalize

d L

um

ina

nc

e

HOR

VER

AXIS


Angular Dependence of CIE Coordinates

SXGA Rotation About Vertical Axis (R3BLP)

0.2

0.25

0.3

0.35

0.4

-40 -30 -20 -10 0 10 20 30 40

Angle (Degree)

CIE

CIE-Y

CIE-X

SXGA Rotation About Horizontal Axis (R3BLP)

0.2

0.25

0.3

0.35

0.4

-40 -30 -20 -10 0 10 20 30 40

Angle (Degree)

CIE

CIE-Y

CIE-X

SXGA Rotation About Vertical Axis (R3BLP)

0.2

0.25

0.3

0.35

0.4

-40 -30 -20 -10 0 10 20 30 40

Angle (Degree)

CIE

CIE-Y

CIE-X

SXGA Rotation About Horizontal Axis (R3BLP)

0.2

0.25

0.3

0.35

0.4

-40 -30 -20 -10 0 10 20 30 40

Angle (Degree)

CIE

CIE-Y

CIE-X


Lifetime of SXGA

0

4

8

12

16

20

24

28

32

36

40

44

48

52

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800

Lum

ina

nce

, fL/

Tem

pe

ratu

re, °

C

Time, hr

Constant Current Full Color SXGA Life Test Raw Data

SXGA Display

Temperature

Color OLED XLTM

SXGA Accelerated Lifetime

(Constant Current Mode; All Pixels On; Initial Lum. 170 cd/m2)

Serial # 90% Life (h) 75% Life (h) 50% Life (h)

R3BN0 5,200 11,500 23,000

R39JL 4,700 10,700 21,500

R3BNJ 5,200 11,500 23,000

Independent Lab measurements


Multichannel Automated Life Test System


Operating SXGA Microdisplays


WUXGA

Features

�7 Million Total Pixel Elements

�Low Voltage Differential Signaling (LVDS) Video

Interface

�24-bit Color Depth (16.7 Million Colors)

�Supported Video Formats

�WUXGA (1920 x 1200)

�HD1080 (1920 x 1080)

�UXGA (1600 x 1200)

�Stereovision for Binocular Application

�Ultra-high Dynamic Range (>100,000:1)

�Horizontal/Vertical Scan Direction Control

�Electronic Image Centering

�Horizontal/Vertical Shift up to 24 pixels

�Low Power Operation (<300mW @ 100 cd/m2)


Summary

• OLED on Silicon microdisplay technology is maturing

• SVGA and SXGA resolution microdisplays with new and improved

features are already products

• WUXGA microdisplays demonstrated - qualification is the next step

• Further improvements in OLED performance are under way

• Even higher resolution microdisplays are under development


The authors wish to thank the staff of eMagin Corporation for

their help in fabricating and testing of the OLED Displays and

U.S. Army for their support.

Acknowledgements


Thank You!!

Active Matrix Full Color OLED...

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