臺灣博碩士論文加值系統

我們成功利用了CuPc捕捉與阻擋電洞的特性，搭配混摻電洞傳輸層之元件結構，開發出一新型電洞傳輸層(複合式電洞傳輸層)。藉由調整此電洞傳輸層內CuPc的摻雜濃度，可以有效的控制電洞在有機電激發光元件內的傳輸特性，達到載子平衡、提升元件發光效率的目的。

在綠光Alq3標準元件方面，套用複合式電洞傳輸層大幅的提升了元件發光效率達1.7倍，在20 mA/cm2電流密度下之最佳元件發光效率為5.96 cd/A，操作電壓為7.64 V。不但如此，應用複合式電洞傳輸層在藍光元件更有不錯的表現。例如在DSA-Ph為客發光體之天藍光元件，20 mA/cm2電流密度下之最佳元件發光效率為16.15 cd/A，操作電壓為6.44 V，CIEx,y色度座標為(0.15, 0.29)，不但不會對發光顏色造成任何影響，更有增加藍光色飽和度的效果。另外，在BD1為客發光體之深藍光元件，20 mA/cm2電流密度下之最佳元件發光效率為5.39 cd/A，操作電壓為6.79 V，CIEx,y色度座標為(0.14, 0.13)，與標準深藍光元件比較，發光效率提升約2倍。

Carrier recombination as well as the balance of holes and electrons is considered to be one of the most important factors that determine the luminance efficiency of OLEDs. In this study, a novel composite hole transport layer (c-HTL) has been developed, which can efficiently control the hole mobility in order to improve hole-electron balance. Improvement in the hole/electron recombination was illustrated by the remarkably high luminance efficiency.

Under 20 mA/cm2 current driven condition, the Alq3-based green device with c-HTL has achieved a luminance efficiency of 5.96 cd/A at 7.64 V, which is 1.7 times higher than that of the standard device. Furthermore, c-HTL has demonstrated even better performance in blue devices. The sky-blue OLED with c-HTL based on the DSA-Ph dopant in MADN host has achieved a luminance efficiency of 16.15 cd/A with a CIEx,y color coordinate of [0.15, 0.29] at 6.44 V (20 mA/cm2) without deteriorating on the color saturation. The deep-blue device with c-HTL based on the BD1 dopant in MADN host has achieved a luminance efficiency of 5.39 cd/A with a CIEx,y color coordinate of [0.14, 0.13] at 6.79 V (20 mA/cm2), which is approximately 2 time higher than that of the standard device.

目 錄
中文摘要……………………………………………...…………………………I
英文摘要…………………………………...……………………………...……Ⅱ
謝誌……………………………………………………………………………Ⅳ
目錄………………………………………………………………………….Ⅴ
圖目錄……………………………………………………………….………Ⅶ
表目錄………………..………………………………………………………Ⅸ
第一章 緒論……………………………………………...……………………1
1-1. 電激發光元件…………………………………..…………………….11-2. 發光效率的定義與量測…...…………………..………………..……3
1-3. 載子平衡之文獻探討……………………………...…....…………....9
1-3-1. 改變電洞、電子注入特性達到載子平衡…………...…..……...91-3-2. 改善電子傳輸能力達到載子平衡提升元件發光效率……..…141-3-3. 利用元件結構之變化來達到載子平衡……………………..…17
第二章 實驗動機……………………………………………..……….……..25 2-1. 前言………………………………………………………………….25 2-2. 先前技藝………………………………………………………….…26 2-3. 實驗目的………………………………………………………….…30
第三章 實驗部分………………………………………...…………….……..31 3-1. 實驗流程圖………..………………………………………………...31 3-2. 實驗材料…………………………………………………………….32 3-2-1. 蒸鍍材料………………………………………………………..32 3-2-2. 基板……………………………………………………………..32 3-2-3. 其它耗材………………………………………………………..32 3-3. 元件製作步驟……………………………………………………….33 3-3-1. ITO基板清洗………………………………………………...…33 3-3-2. ITO前處理…………………………………………………...…33 3-3-3. 薄膜蒸鍍……………………………………………………..…34 3-3-4. 元件封裝…………………………………………………….….37 3-3-5. 元件特性及壽命測試…………………………………………..38 3-4. 薄膜分析步驟…………………………………………………….....40第四章 結果與討論………………………………………………….……….41 4-1. 含有c-HTL之綠光元件…………………………………………….41 4-2. 含有c-HTL之藍光元件…………………………………………….51第五章 結論………………………………………………...……………….65參考文獻……………………………………………………………………….67



圖目錄
圖1-1. 有機發光二極體元件結構圖…….………………………….……..…1
圖1-2. 由電洞與電子注入至光線向元件外部發光為止的過程圖………....6
圖1-3. 含有CuPc緩衝層之元件結構…………………………….………...12
圖1-4. 不同CuPc厚度的元件特性圖…………………………..…….….…12
圖1-5. 不同SiO2厚度的元件特性比較……………………….…………….13
圖1-6. 不同SiOxNy厚度的元件特性圖…………..…………….……..........14
圖1-7. 不同Alq3蒸鍍速率的電子傳輸能力與元件發光效率圖..………….15
圖1-8. TRZ1-TRZ4分子結構圖………………….........…………..…......…16
圖1-9. 多量子井元件結構及效率表現…..…………………….…………...18
圖1-10. Firpic HBL元件結構及能階圖..………………...………..…...…20
圖1-11. Li doped Alq3元件B-I-V圖………………...……………......….21
圖1-12. 電子/電洞在PFO與混摻5% TPP之PFO的TOF量測結果….….…22
圖1-13. TPD、Rubrene和DCM1之能階圖..……………............……….....23
圖1-14. 不同混摻方式元件之亮度-電流密度圖……..………………..…….24
圖2-1. 標準元件與含有CuPc或Rubrene元件的電性比較圖……….……28
圖2-2. NPB、CuPc及Rubrene之能階圖………………….……………….29
圖2-3. 量子井元件結構………………………………………………......…30
圖3-1. 薄膜蒸鍍單元示意圖…………………………………………….….34
圖3-2. 蒸鍍機之內部配置圖…..………………………………………...….36
圖3-3. 元件發光面積示意圖………………………………………………..37
圖3-4. 封裝單元示意圖…………………………………………………..…38
圖3-5. 元件穩定度測試之示意圖..……………………………….……...…39
圖3-6. AFM操作原理示意圖……………………………………………….40
圖4-1. c-HTL及Alq3之能階圖…………………………………….……….42
圖4-2. 操作電壓及發光效率對CuPc摻雜濃度之趨勢圖(1)………….…...42
圖4-3. 操作電壓及發光效率對CuPc摻雜濃度之趨勢圖(2)………….…..46
圖4-4. hole-only元件之能階及電性表現圖……………………………..…50
圖4-5. 電洞在c-HTL中傳輸之示意圖……………………………….….…51
圖4-6. 40 nm CuPc薄膜之吸收光譜……………………………………..…52
圖4-7.圖4-8. 含c-HTL及正常天藍光(DSA-Ph)元件之EL光譜圖…………..…..54藍光元件之亮度對量測角度趨勢圖………………………………..55
圖4-9. MADN之放射光譜及BD1之吸收光譜………….…………………56
圖4-10. 藍光元件之電流密度對電壓圖.……………….…………………....58
圖4-11. 藍光元件之發光效率對電流密度圖..……………………………....59
圖4-12. 藍光元件之穩定度測試結果……………………..…………..……..60
圖4-13. 藍光元件之操作電壓對操作時間圖……………………….……….61
圖4-14. NPB及c-HTL之AFM量測結果………………………….……….63

表目錄
表1-1.表1-2.表4-1.表4-2.表4-3.表4-4.表4-5. 光度學與放射學的對應名稱與單位…….……….…………………..4不同電子注入陰極之元件特性比較………………….……………..1120 mA/cm2下之綠光元件效率表現(1)…………………………...…4320 mA/cm2下之綠光元件效率表現(2)…………………………...…4620 mA/cm2下之綠光元件效率表現(3)………………………….…..4820 mA/cm2下之藍光元件效率表現(1)…...………………………....5320 mA/cm2下之藍光元件效率表現(2)……………………………...59

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