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有機發光二極體(OLED)製作技術
Fabrication Technology of Organic Light
Emitting Diodes (OLED)
莊賦祥 教授
國立虎尾科技大學 光電工程系
103年10月24日
Institute of Electro-Optical and Materials Science, National Formosa University
大綱
• OLED基本原理簡介
(元件結構、能帶圖、基本材料)
• OLED(有機)與LED(無機)比較
• OLED Lighting發展概況
2
Institute of Electro-Optical and Materials Science, National Formosa University
OLED基本原理簡介
OLED: Organic Light Emitting Diode
PLED : Polymer Light Emitting Diode
LEP
<1,000
: Light Emitting Polymer
 Molecular Weight 
10,000 ~ 80,000
Small-molecule
Polymer
Source : Global Photonic Energy Corporation (GPEC)
3
Institute of Electro-Optical and Materials Science, National Formosa University
Benzene
C6H6
4
Institute of Electro-Optical and Materials Science, National Formosa University
Advantages of OLED
Self emitting : no backlight demands
Wide viewing angle : 170o with no brightness loss
Large area display
Full colors
high brightness (>100 cd/m2 at 3V) and high contrast ratio
Rapid response time : ~ msec
Small thickness (<1.5 mm) and light weight
Low power consumption : < 5V, 6-12 mW/inch2
Fabrication is easy and low cost : 20-30% lower than TFT LCD
Flexible display
Passive or active matrix technology (PM or AM)
Basic operation theory and device structures
Vacuum level
1
3.1eV
2.3eV
2
LUMO
Light
3 emission
0.8eV
3.2eV
`
Xe(TPD)=1.4eV
0.6eV
3.7eV
4
5
LUMO: Lowest unoccupied
molecular orbital
HOMO: Highest occupied
molecular orbital
2.7eV
4.9eV
5.5eV
0.6eV
HOMO
E/eV
ITO
0.3eV
TPD
`
Alq3
Xh(Alq3)=0.9eV
5.8eV
Mg
High work function ITO, low work function Mg
The electrons injected from Mg are captured by the traps in Alq3.
Electrons move by hopping.
7
Institute of Electro-Optical and Materials Science, National Formosa University
Vacuum level
1
3.1eV
2.3eV
2
LUMO
Light
3 emission
0.8eV
3.2eV
`
Xe(TPD)=1.4eV
0.6eV
3.7eV
4
5
5.5eV
0.6eV
HOMO
ITO
TPD
AlQ3
Hole mobility
10-3
very low
2.7eV
4.9eV
E/eV
(cm2/V.s)
0.3eV
TPD
`
Alq3
Xh(Alq3)=0.9eV
5.8eV
Mg
Electron
mobility
10-5
The electrons injected from Mg are captured by the traps in Alq3.
The holes inject into TPD and move faster than electrons in Alq3.
Hole mobility in Alq3 is very low  holes accumulated at the TPD/Alq3
interface
HOMO hole barrier (0.3eV) < LUMO electron barrier (0.8eV).
So holes reach AlQ3 layer more easily  The light emission originates
from the AlQ3 layer.
8
Institute of Electro-Optical and Materials Science, National Formosa University
Institute of Electro-Optical and Materials Science, NationalPicture
Formosa
University
source:
RiTdisplay
LUMO
HOMO
Polymer
LED
Material characteristics (1)
(1) Electron Transport Layer (ETL):
 Only can electrons transport (hole mobility very low)
– Such as metal-chelate: AlQ3, BeBq2
– Thermal stable, film morphology good
– e- mobility in AlQ3 is 5x10-5 cm2/V.s
 The thickness in OLED <1000 Å  to decrease the
driving voltage
Small molecule
(1) Electron Transport Layer (ETL)
Polymer
(2) Hole Transport Layer (HTL)
AlG3 Green
DPVBi Blue
(3) Emitting Layer (EML)
(5) Hole Injection Layer (HIL)
(4) Doping materials
QA Green
PeryleneB
lue
DCJT Red
610-690nm
Coumarin-6 green
500nm
13
Rubrene Blue-green
Institute of Electro-Optical and Materials Science, National Formosa University
Material characteristics (2)
(2) Hole Transport Layer (HTL)
– Easy to recrystallize due to aging or thermal heating (the
main problem in OLED)
– The higher the glass transfer temp. (Tg), the better the
thermal stability: TPD(60oC), NPB(98oC), AlQ3(175oC)
– TPD coated on ITO easy to recrystallize in few hours in
air
Small molecule
(1) Electron Transport Layer (ETL)
Polymer
(2) Hole Transport Layer (HTL)
AlG3 Green
DPVBi Blue
(3) Emitting Layer (EML)
(5) Hole Injection Layer (HIL)
(4) Doping materials
QA Green
PeryleneB
lue
DCJT Red
610-690nm
Coumarin-6 green
500nm
15
Rubrene Blue-green
Institute of Electro-Optical and Materials Science, National Formosa University
Material characteristics (3)
(3) Emitting layer (EML) or Host Emitting Layer:
– Self emitting and able to transport electrons or holes
{
{
AlQ3
520 nm Green
BeBq2
516 nm Green
Sanyo Electrical
DPVBi
475 nm Blue
Idemitsu Kosan
Balq+Perylene
475 nm Blue
Kodak
AlQ3+Zn2(oxz)
Cl
470 nm Blue
AlQ3+Coumarin
500 nm
Green
AlQ3+DCM
596 nm Red
(4) Emissive dopant or guest material
• Dopant amount: 0.5-1%
16
Institute of Electro-Optical and Materials Science, National Formosa University
Small molecule
(1) Electron Transport Layer (ETL)
Polymer
(2) Hole Transport Layer (HTL)
AlG3 Green
DPVBi Blue
(3) Emitting Layer (EML)
(5) Hole Injection Layer (HIL)
(4) Doping materials
QA Green
PeryleneB
lue
DCJT Red
610-690nm
Coumarin-6 green
500nm
17
Rubrene Blue-green
Institute of Electro-Optical and Materials Science, National Formosa University
螢光
磷光
Picture source: RiTdisplay
Several dye compounds commonly used as color emitters in OLED.
IEEE J. Select. Top. In QE, 6(6), 2000
Passive Matrix
Row driver
Column driver
Institute of Electro-Optical and Materials Science, National Formosa University
Active Matrix OLED (AMOLED)
Institute of Electro-Optical and Materials Science, National Formosa University
Institute of Electro-Optical and Materials Science, National Formosa University
Electrode Materials
Anode:
High work-function metals
Indium-tin-oxide (ITO) 銦 錫(Sn, Tin) 氧化物
CNx
Conducting polymer-polyaniline, PEDOT
Aluminum Doped Zinc Oxide (AZO)
Indium Doped Zinc Oxide (IZO)
Cathode:
Low work-function metals or alloys
LiF/Al
Mg:Ag
Li:Al Li2O:Al
CaOx Ca:Al
CsF /Al
Cs :Alq3/Al
Yb/CsF (S. T. Lee, ICEL-4, 2003)
23
Institute of Electro-Optical and Materials Science, National Formosa University
大綱
• OLED基本原理簡介(元件結構、能帶圖、
基本材料)
• OLED(有機)與LED(無機)比較
• OLED Lighting發展概況(各公司照明面板
展示)
24
Institute of Electro-Optical and Materials Science, National Formosa University
OLED和LED比較
LED照明
OLED照明
共同點
點光源
指向性強
元件小
大面積難輕量化
屬固態照明
面光源
擴散光源
具高發光效率
潛力,將超過
薄型、輕量、透
螢光燈
明
節能、環保
大面積
source: http://www.digitimes.com.tw/tw/rpt/rpt_show.asp?CnlID=3&v=20090609-176&ct=1
25
Institute of Electro-Optical and Materials Science, National Formosa University
OLED照明於面光源應用優勢圖
A
Source :NEDO/ITRI/IEK(01/2009)
26
Institute of Electro-Optical and Materials Science, National Formosa University
OLED/LED比較
Source :ITRI/IEK(01/2009)
27
Institute of Electro-Optical and Materials Science, National Formosa University
Source : Panasonic, PIDA整理 (2012)
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Institute of Electro-Optical and Materials Science, National Formosa University
照明光源演進歷史及未來發展預測圖
29
Source:Navigant Consulting
Institute of Electro-Optical and Materials Science, National Formosa University
Compound Semiconductor, 5(9), 1999
OLED照明於日本市場的應用領域
Source :中国OLED网
31
Institute of Electro-Optical and Materials Science, National Formosa University
種類
LED
OLED
32
優點
缺點
體積小
壽命長
低驅動電壓
耗電量低
耐震性佳
成本高昂
功率小
光衰大
顯色性:>80 Ra
色溫:選擇範圍較窄
發熱量高
因點光源故具有刺眼眩光和閃爍,
光汙染嚴重。
自發光,視角廣達165°以上
反應時間快(~1μs)
高亮度(100-14000 cd/m2)
低操作電壓(3-9 V DC)
面板厚度薄(2 mm)
可製作大尺寸與可撓曲性面板
製程簡單,具有低成本的潛力
(30-40% of TFT-LCD)
壽命較LED短
不能實現大尺寸屏幕的量產
存在色彩純度不夠的問題流明效
率低(16-38 lm/W)
Institute of Electro-Optical and Materials Science, National Formosa University
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