我們利用高真空蒸鍍系統，於透明的導電陽極-氧化錫銦玻璃基板上成長有機薄膜與金屬陰極，進而完成白光有機電激發光元件的製備。在我們的研究中，利用多層結構的方法來完成有機電機發光元件的研製，其完整結構為ITO/NPB /Host：Firpic：Ir(DBQ)2(acac) /TPBI /Mg:Ag ，其中發光層我們分別利用三種不同的主體材料mCP，TCTA以及CBP來製作元件。
我們有系統地探討不同的主體材料對白光有機發光二極體之光電特性影響，經研究證實利用高能隙主體材料可以有效提升白光有機電激發光元件的亮度。證據顯示由於高能隙主體材料的使用能夠讓主客體材料之間的能量轉移更加順利，使得有機發光二極體的亮度能夠更進一步提升。在本研究中，我們利用高能隙的主體材料轉移能量給發藍光的客體材料FIrpic 和發紅光的客體材料Ir(DBQ)2(acac)，藉由混合藍光與紅光得到白光。

Organic light emitting devices were deposited on Indium tin oxide (ITO) substrate by high vacuum evaporator system. In our study, the device configurations of white organic light emitting diodes (WOLEDs) using multilayer structure were ITO/NPB /Host：Firpic：Ir(DBQ)2(acac) /TPBI /Mg:Ag. Three different host materials, including mCP, TCTA, and CBP, are individually used in the emitting layer to fabricate the devices.
Effects of different host materials on the photoelectronic characteristics of white-light organic light-emitting diodes have been systematically investigated. It is proved that with the use of suitable high energy-gap host materials, the brightness of WOLEDs can be significantly improved. Evidence showed that the use of the high energy-gap materials make the energy transfer between the host and guest materials easier. Hence, the brightness of OLED can be further enhanced. In this study, the energy is transferred from the high energy-gap host material to the guest materials Firpic and Ir(DBQ)2(acac), and then the blue and red light is produced by the Firpic and Ir(DBQ)2(acac), respectively. By the mixture of the red and blue light, the white light emission is achieved.

CONTENTS

Publications and Preprints I
ABSTRACT (in Chinese) II
ABSTRACT (in English) III
Acknowledgment V
FIGURE CAPTION...............................................................................VI
CONTENTS.......................................................................................... VII

Chapter 1. Introduction 1
1.1 Background 1
1.2 Motivation 2
1.3 Organization of This Thesis 3
Chapter 2. Basic Concepts and Experimental Procedure 4
2.1 Basic Concepts 4
2.1.1 Electroluminescence in Organic Materials 4
2.1.2 Charge Carrier Injection and Transport 5
2.1.3 Luminescent Mechanisms of Organic Materials 6
2.2 Experimental Procedure 8
2.2.1 ITO Substrate Etching and Cleaning 9
2.2.2 Deposition of Organic Thin Films and Electrodes 9
2.2.3 Measurement 9
Chapter 3. Photoelectronic Characteristics for White Organic Light-Emitting Diodes with Different High Energy-Gap Hosts
3.1 Introduction 10
3.2 Experiments 10
3.3 Results and Discussion 11
3.4 Conclusions 12
Chapter 4. Summary and Suggestions for Future Work
4.1 Summary……………………………………………………. 13
4.2 Suggestions for future work………………………………… 13
References
Figures

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