OLED Display Fundamentals and Applications

Series Editor's Foreword ix

Preface xi

1 Introduction 1

2 OLED Display Structure 5

2.1 OLED Definition 5

2.2 OLED Device Principles and Mechanisms 8

2.2.1 Basic Device Structure 8

2.2.2 Light Emission 10

2.2.3 Emission Efficiency 26

2.2.4 Lifetime and Image Burning 30

3 OLED Manufacturing Process 37

3.1 Material Preparation 37

3.1.1 Basic Material Properties 37

3.1.2 Purifi cation Process 41

3.2 Evaporation Process 42

3.2.1 Principle 42

3.2.2 Evaporation Sources 47

3.3 Shadow Mask Patterning 54

3.4 Encapsulation 57

3.4.1 Dark Spot and Edge Growth Defects 57

3.4.2 Light Emission from the Bottom and Top of the OLED Device 58

3.5 Problem Analysis 61

3.5.1 Ionization Potential Measurement 61

3.5.2 HPLC Analysis 64

3.5.3 Cyclic Voltammetry 65

4 OLED Display Module 69

4.1 Comparison between OLED and LCD Modules 69

4.2 Basic Display Design and Related Characteristics 71

4.2.1 Luminous Intensity, Luminance, and Illuminance 71

4.2.2 OLED Current and Power Efficiencies 76

4.2.3 Color Reproduction 80

4.2.4 Uniform Color Space 874.2.5 White Point Determination 88

4.3 Passive-Matrix OLED Display 91

4.3.1 Structure 91

4.3.2 Pixel Driving 93

4.4 Active-Matrix OLED Display 96

4.4.1 OLED Module Components 96

4.4.2 Two-Transistor One-Capacitor (2T1C) Driving Circuit 97

4.4.3 Ambient Performance 100

4.4.4 Subpixel Rendering 101

5 TFT Substrate for OLED Driving 105

5.1 TFT Structure 105

5.2 TFT Process 110

5.2.1 Low-Temperature Polysilicon Process Overview 110

5.2.2 Thin-Film Formation 111

5.2.3 Patterning Technique 112

5.2.4 Excimer Laser Crystallization 116

5.3 MOSFET Basics 120

5.4 LTPS-TFT-Driven OLED Display Design 122

5.4.1 OFF Current 123

5.4.2 Driver TFT Size Restriction 124

5.4.3 Restriction Due to Voltage Drop 125

5.4.4 LTPS-TFT Pixel Compensation Circuit 132

5.4.5 Circuit Integration by LTPS-TFT 139

6

Takatoshi Tsujimura is the General Manager of the Konica Minolta Technology Center. He received a SID award for the development of a scalable AMOLED backplane and the world s largest 20-inch OLED prototype, has worked for Kodak and IBM, and is the SID Japan Chapter vice chair. Mr. Tsujimura was selected as one of the "10 best engineers/researchers in the 10 best Japanese companies" by Nikkei Electronics magazine.

"Overall however, despite a few shortcomings, this work will be a valuable and currently unique resource for anyone interested in learning about OLEDs in general and of particular interest to engineers, managers, and other industry professionals entering the field or expanding their areas of expertise." ( Information Display , 1 May 2012)

"Overall however, despite a few shortcomings, this work will be a valuable and currently unique resource for anyone interested in learning about OLEDs in general and of particular interest to engineers, managers, and other industry professionals entering the field or expanding their areas of expertise." ( Information Display , 1 May 2012)