臺灣博碩士論文加值系統

本篇論文之目的係設計及製作高效率有機電激發光元件，藉由摻雜紅光 (4-(dicyanomethylene)-2-tert-butyl-6-1,1,7,7- tetramethyljulolidyl-9-enyl)-4H-pyran) 與藍光(4,4′-bis-[2-[4-(N,N-diphenylamino)-phenyl-1-yl]-vinyl-1-yl]-1,1′-biphenyl, (DPAVBi) and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine, N-BDAVBi)螢光材料以及綠光(tris-(phenylpyridine)iridium)磷光材料，並且調變有機材料發光層之厚度與濃度，製造出高效率的白光有機電激發光元件。在紅綠光發光層中，找出最適合摻雜紅光材料位置，利用綠光材料之載子複合區的能量轉移，使得綠光能量部分轉移至紅光，但效率卻不會因此而大幅度降低。實驗的結果顯示此白光結構在輸入電壓為5V之下其效率分別為12.7 (DPAVBi) 與14 (N-BDAVBi) cd/A，在 100 mA/cm2電流密度下之驅動電壓分別為7.54與8.94V，其色座標分別為(0.416, 0.485)與(0.386, 0.492)。
此外，我們也研發出具備電子傳輸能力之2,2''-bis[5-phenyl-2-(1,3,4)oxadazolyl]biphenyl (OXD) 作為發光層之主體材料，並製作出單發光層及雙發光層之高效率藍光及藍綠光有機電激發光元件。在此實驗中藉由一高電子傳輸效率材料 (OXD) 並搭配電洞傳輸特性的主體材料 (N,N’-dicarbazolyl-3,5-benzene)作為藍光磷光材料 (iridium(III)bis(4,6-(di-fluorophenyl)-pyridinato-N,C2’) picolinate) 之主體以達到雙重發光層元件，藉由雙發光層而達到延展載子複合區的特性，可確實的降低因為介面載子濃度過高，而造成的三重態載子能量焠熄。實驗的結果顯示，藉由導入雙發光層後，藍光及藍綠光磷光元件之最高效率可達 11.8及 12.4 cd/A。

In this thesis, we researched in high efficiency organic light-emitting devices (OLEDs). With introducing red, 4-(dicyanomethylene)-2-tert-butyl-6-1,1,7,7- tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), and blue, 4,4′-bis-[2-[4-(N,N-diphenylamino)-phenyl-1-yl]-vinyl-1-yl]-1,1′-biphenyl (DPAVBi) and N-(4-((E)-2-(6-((E)-4-(diphenylamino)styryl)naphthalen-2-yl)vinyl)phenyl)-N-phenylbenzenamine (N-BDAVBi), fluorescent materials and green, tris-(phenylpyridine)iridium (Ir(ppy)3), phosphorescent material and modifying the layer structures to manufacture high efficiency white OLEDs. Among green/red emission zone, the suitable position with doping the red fluorescent material, DCJTB, was founded to serve the energy transfer by phosphorescent sensitization with green phosphorescent emitter, Ir(ppy)3, and red fluorescent emitter. As the results of experiments, the current efficiencies of our white OLEDs attended to 12.7 and 14 cd/A at applied voltage was 5 V with DPAVBi and N-BDAVBi, respectively. Besides, the driving voltage and color coordinates were 7.54, 8.94 V and (0.416, 0.485), (0.386, 0.492) at 100 mA/cm2, respectively.
Furthermore, a new electron transport material, 2,2''-bis[5-phenyl-2-(1,3,4)oxadazolyl]biphenyl (OXD), was used as the host of the green-blue and blue phosphorescent OLEDs. With introducing the hole-transporting material, N,N’-dicarbazolyl-3,5-benzene (mCP), as the host of the blue dopant, iridium(III)bis(4,6-(di-fluorophenyl)-pyridinato-N,C2’) picolinate (FIrpic), the double emitting layer (EML) blue phosphorescent OLED was fabricated. From the expansion of recombination zone with double EML blue phosphorescent OLEDs, the exciton concentration in unit area decreased efficiently and reduced the triplet-triplet annihilation. Thus, the maximum current efficiencies of blue and blue-green phosphorescent OLEDs with double EML were 11.8 and 12.4 cd/A, respectively.

Figure and Table Indices 7

Chapter 1 Introduction 11
1.1 Introduction of OLED 12
1.2 Introduction of White OLED 14
1.3 Efficiency improvement of phosphorescent OLED 18
1.4 Experiments 23
1.5 Motivation 24
1.6 Thesis organization 25

Chapter 2 Three-band White Organic Light-emitting Device 27
2.1 Blue Fluorescent OLED in CBP Host 28
2.2 Layer Structure Optimization of Green-blue OLED 32
2.3 Layer Structure Optimization of White OLED 40
2.4 White OLED with Different Spacer Materials 48
2.5 White OLED with Different Host Materials 52
2.6 Improvement of Blue Emitter in White OLED 57

Chapter 3 Double EML Blue OLED 67
3.1 Blue Phosphorescent OLED in OXD Host 68
3.2 Optimization of Blue Phosphorescent OLED 70
3.3 Optimization of Blue-green Phosphorescent OLED 76
3.4 Double EML Blue OLED with Different Host Materials 80
3.5 Layer Structure Optimization of Double EML Blue OLED 84

Chapter 4 Summary and Future Works 93
4.1 Summary 93
4.2 Future Works 94

References: 95

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