Abstract (in Chinese)…………………………………………I Abstract (in English)…………………………………………Ⅱ Content……………………………………………………………Ⅲ Figure and Table Captions……………………………………Ⅵ Chapter 1 Introduction………………………………………1 Chapter 2 Principle of OLED………………………………6 2-1 The Mechanism of OLED…………………………………6 2-1-1 Electrical characteristics of OLED…………………6 2-1-2 Electroluminescence of OLED…………………………8 2-2 Various Structures of OLED………………………………9 2-3 Factors of Effects on Performance of OLED…………11 2-4 Efficiency Calculation…………………………………12 Chapter 3 Experimental Procedures and Systems………14 3-1 Experimental Preparation………………………………14 3-1-1 Substrate Cleaning……………………………………14 3-1-2 Substrate etching process……………………………15 3-2 Growth system and procedures……………………………15 3-2-1 Deposition System………………………………………15 3-2-2 Materials…………………………………………………16 3-2-3 Deposition of thin films………………………………17 3-3 Encapsulation procedure……………………………………18 3-3-1 RF magnetron sputtering system…………………………18 3-3-2 Encapsulation procedure…………………………………18 3-4 Measurements……………………………………………………19 3-4-1 Electrical Characteristic………………………………19 3-4-2 Optical Characteristics…………………………………20 3-4-3 Surface Morphology…………………………………………21 Chapter 4 Modeling and Simulation……………………………22 4-1 The I-V Model……………………………………………………22 4-1-1 Equations defining the model………………………………22 4-2 The EL Model………………………………………………………27 4-2-1 Equations defining the model…………………………………28 4-3 Result and Discussion……………………………………………30 4-3-1 Electron Transport Layer (Alq3) with nitrogen incorporation………………………………………………………30 4-3-2 Hole Transport Layer (TPD) with nitrogen incorporation………………………………………………………34 4-3-3 Nitrogen Incorporation in both ETL and HTL………………36 4-4 Summary…………………………………………………………………37 Chapter 5 Conclusion and Prospect……………………………………39 Figure Captions Chapter 2 Fig. 2-1 The OLED structure Fig. 2-2 The energy level diagram of bi-layer OLED Fig. 2-3 Schematic representation of pathways for singlet decay as well as triplet excitation and decay Fig. 2-4 Various structures of OLED Chapter 3 Fig. 3-1 The thermal vacuum evaporation system Fig. 3-2 (a) The molecular structure of TPD (b) The molecular structure of Alq3 Fig. 3-3 The top view of encapsulation structure Fig. 3-4 The RF magnetron sputtering system Fig. 3-5 The photoluminescence apparatus Fig. 3-6 The electroluminescence apparatus Chapter 4 Fig. 4-1 The bi-layer OLED structure Fig .4-2 Schematic diagram showing the relaxation of trapped electrons in Alq3 with a minority hole Fig. 4-3 Simulation and measured I-V curves for OLED with Alq3 incorporated by nitrogen at various pressures Fig. 4-4 The elemental composition of Alq3 with nitrogen- incorporation measured by AES Fig. 4-5 The elemental composition of Alq3 without nitrogen incorporation measured by AES Fig. 4-6 Electrons transport in the OLED with nitrogen-incorporation Fig. 4-7 Simulation and measured L-V curves for OLED with Alq3 incorporated by nitrogen at various pressures Fig. 4-8 The L-I characteristics of OLED with nitrogen-incorporation to Alq3 Fig. 4-9 Current efficiency-Current density characteristics of OLED with nitrogen-incorporation to Alq3 Fig. 4-10 Power efficiency-Current density characteristics of OLED with nitrogen-incorporation to Alq3 Fig. 4-11 The SEM of Alq3 surface Fig. 4-12 The PL spectrum of Alq3 (ETL, EML) Fig. 4-13 (a) The EL spectra of OLED without nitrogen treatment (b) The EL spectra of OLED with nitrogen- incorporation to Alq3 Fig. 4-14 Simulation and measured I-V curves for OLED with TPD incorporated by nitrogen at various pressures Fig. 4-15 The mechanism of hole conduction in HTL(TPD) Fig. 4-16 Simulation and measured L-V curves for OLED with TPD incorporated by nitrogen at various pressures Fig. 4-17 The L-I characteristics of OLED with nitrogen-incorporation to TPD Fig. 4-18 The Current efficiency-I characteristics of OLED with nitrogen-incorporation to TPD Fig. 4-19 The Power efficiency-I characteristics of OLED with nitrogen-incorporation to TPD Fig. 4-20 The SEM of TPD surface Fig. 4-21 Simulation and measured I-V curves for OLED with nitrogen-incorporation to both Alq3 and TPD Fig. 4-22 Simulation and measured L-V curves for OLED with nitrogen -incorporation to both Alq3 and TPD Fig. 4-23 The L-I characteristics of OLED with nitrogen -incorporation to both Alq3 and TPD Fig. 4-24 The diagram of carriers transport in OLED treated Fig. 4-25 The Current efficiency versus Current density characteristics of OLED with nitrogen- incorporation to both Alq3 and TPD Fig. 4-26 The Power efficiency versus Current density characteristics of OLED with nitrogen - incorporation to both Alq3 and TPD Fig. 4-27 The comparison between I-V characteristics of OLED with nitrogen-incorporation to different organic layer Fig. 4-28 The comparison between L-V characteristics of OLED with nitrogen-incorporation to different organic layer Fig. 4-29 The comparison between Current efficiency-I characteristics of OLED with nitrogen- incorporation to different organic layer Fig. 4-30 The comparison between Power efficiency-I characteristics of OLED with nitrogen- incorporation to different organic layer