臺灣博碩士論文加值系統

本篇論文主要研究高效率藍色磷光發光二極體（organic light-emitting，OLED），使用能幫助電洞傳遞的咔唑基團（Carbazole），同時搭配兩個幫助電子傳輸的三唑基團（Triazole）與吡啶基團（Pyridine），合成四支具雙極性的一系列新穎的PCT主體材料，藉由調變元件內各膜層的厚度及客發光體材料摻雜濃度，使主體材料內載子平衡，達到元件最佳效率表現。另外以咔唑基團搭配也能幫助電子傳遞的咪唑基團（Imidazole），合成的一支具雙極性的o-DiCbzBz主體材料，主體材料需要雙極性的搭配是因為咔唑基團有很好的電洞傳輸性質之外，又兼具高三重態能量，搭配其他具電子傳輸特性的基團，作為藍光元件發光層的主體材料；本篇論文另外一個主題為開發具有AC-EL（alternating current-electroluminescence）能力的有機發光二極體，藉由材料的選擇、利用材料混合共蒸鍍來調變其能階分佈，設計並改善載子的傳遞路徑，利用雙邊對稱結構以期元件在交流電驅動下，能達到正負半週階能發光的現象。
本篇論文第一章我們首先介紹了有機發光二極體的發展，介紹了有機發光的特性及物理機制，分析OLED的優勢及未來性，以及目前所面臨的瓶頸。第二章為本文元件的實驗流程架構，所使用的量測系統與定義所用之單位；第三章的主題為四支由台大化學所梁文傑實驗室所合成的材料之主體材料PCT1~4，摻雜客發光體材料FIrpic用於藍色磷光系統，進行一系列元件之效率優化。首先，我們製作了各主體材料的唯載子元件，觀察FIrpic在主體材料內對於載子的影響，優化過程中我們調變FIrpic的摻雜濃度，在進行電子傳輸層厚度及發光層厚度的調變，希望能達到元件發光層內電洞與電子的數量之平衡，而降低元件驅動電壓及提升元件發光效率，另外選出兩支材料進行發光層部分摻雜的實驗，觀察復合發光區的位置分佈及載子在介面上的傳輸情形，本節尾端藉由量測元件之光激發致螢光頻譜，探討藍光元件壽命衰減之機制。
第四章為使用台大化學所梁文傑實驗室所開發藍光主體材料o-DiCbzBz，搭配商用電子傳輸層材料DPPS和TmPyPB及一支ET特性的主體材料BTBP，以低濃度摻混進主體材料中，形成混合式的發光層，接續藉由調整摻雜入的厚度，來達到載子最佳平衡，降低驅動電壓、提升元件電流效率及外部量子效率。第五章為開發雙注入型交流驅動式有機發光二極體（double injection AC-OLED），選擇合適能階的有機材料，配合雙邊金屬電極，以期能在交流電驅動下，達到正負半週皆能發光之元件。第六章為本論文之結論。

In this thesis, the first part is disclosed a series of novel host materials combining hole-transporting moiety, Carbazole, and electron-transporting moieties Triazole and Pyridine, as bipolar host to fabricate high efficiency blue phosphorescence organic light-emitting diode (OLED) with the blue phosphorescent emitting dopant, FIrpic. Second part is the development of an alternating current (AC)-driven organic light emitting diodes (OLED). We co-depositied these materials to modulate their energy level. We designed a symmetrical device structure, to achieve the lit-on OLED at positive and negative half-cycle stage in AC driven.
In the chapter I, we introduced the OLED relatives, including history, principle, recent development of OLED in materials and device. Chapter II described the experimental detail to fabricate the OLED devices and some know-how.
Chapter III results and discussion, we characterized four novel host materials by, measuring of the absorption spectrum, highest occupied electronic energy levels (HOMO), lowest electronic unfilled full energy level (LUMO), and photoexited fluorescence spectrum. They were employed to host material of emitting layer (EML) of blue OLEDs. Varying the dopant concentration, and the thickness of electron-transporting layer to achieve electron-hole balance for high efficiency blue OLED. Furthermore, we also investigated the main recombination zone of EML using partial doped dopant at distinct EML position.
Chapter IV introduced a method using a partial mixed host as a part of EML, combining o-DiCbzBz with various electron-transporting hosts, such as BTBP, DPPS, and TmPyPB. Varying the layer thickness of partial mixed host in EML, the main recombination zone was enlarged and the carrier balance could be achieved because we obtained a great improvement in the device efficiency. Chapter V demonstrated an alternating current (AC)-driven organic light emitting diodes (OLED) by modifying the carrier injection layer. The purpose was to fabricate a direct AC-driven OLED with any dielectric layer. The last Chapter VI was the thesis conclusions.

目錄 vii
表目錄 ix
圖目錄 xi
符號說明 xv
第一章 緒論 1
1.1 前言 1
1.2 有機發光二極體發展歷史 1
1.3 有機發光二極體發光原理 2
1.4 有機發光二極體能量轉移機制 3
1.5 有機發光二極體材料發展 4
1.6 主體材料之發展 6
1.7 研究動機 9
第二章 有機發光二極體實驗製程與量測介紹 10
2.1 黃光微顯製程 10
2.2 真空熱蒸鍍製成設備 11
2.2.1 陽極氧電漿表面處理 11
2.2.2 有機材料與陰極熱蒸鍍 12
2.2.3 元件封裝 12
2.3 量測系統 13
第三章 不同主體材料對藍色磷光有機發光二極體之表現 15
3.1 主體材料之材料特性 15
3.2 各主體材料之唯載子元件 18
3.3 不同主體材料作為藍色磷光主體材料的研究 20
3.4 PCT1 作為藍色磷光主體材料 20
3.4.1 摻雜濃度調變 21
3.4.2 電子傳輸層厚度調變 24
3.4.3 發光層厚度調變 26
3.4.4 發光層部分摻雜之探討 28
3.4.5 PCT1藍色磷光材料摻雜濃度調變 31
3.5 PCT2 作為藍色磷光主體材料 34
3.5.1 摻雜濃度調變 34
3.5.2 電子傳輸層厚度調變 37
3.5.3 發光層厚度調變 39
3.6 PCT3 作為藍色磷光主體材料 41
3.6.1 摻雜濃度調變 41
3.6.2 電子傳輸層厚度調變 44
3.6.3 發光層厚度調變 46
3.7 PCT4 作為藍色磷光主體材料 48
3.7.1 摻雜濃度調變 48
3.7.2 電子傳輸層厚度調變 51
3.7.3 發光層厚度調變 53
3.7.4 發光層部分摻雜之探討 55
3.7.5 藍色磷光元件壽命之探討 59
3.8 PCT主體材料元件比較 61
第四章 o-DiCbzBz部分摻雜不同ET材料之發光層 64
4.1 o-DiCbzBz部分摻雜DPPS作為發光層 64
4.1.1 電子傳輸層厚度調變 65
4.1.2 摻雜濃度調變 67
4.1.3 混合式發光層厚度調變 69
4.1.4 混合式發光層部分摻雜之探討 71
4.2 o-DiCbzBz部分摻雜TmPyPB作為發光層 75
4.2.1 電子傳輸層厚度調變 76
4.2.2 摻雜濃度調變 78
4.2.3 混合式發光層厚度調變 80
4.2.4 混合式發光層部分摻雜之探討 82
4.3 o-DiCbzBz部分摻雜BTBP作為發光層 84
4.3.1 摻雜濃度調變 85
4.3.2 電子傳輸層厚度調變 87
4.4 統一元件架構中混合式發光層摻雜不同ET材料 89
第五章 交流驅動式有機發光二極體 92
5.1 CuPc作為載子傳輸層應用在AC-OLED 92
5.1.1 單層CuPc元件電性探討 92
5.1.2 不同材料之元件電性探討 93
5.1.3 金屬氧化物摻雜CuPc調變能階 95
5.2 以Exciplex作為發光層應用在AC-OLED 99
5.2.1 利用絕緣層注入電荷型 99
5.2.2 直接注入電荷型 100
第六章 結論 102
6.1 結論 102
6.2 未來工作 103
參考文獻 104

Tang, C. W., VanSlyke, S. A. (1987). Organic electroluminescent diodes. Applied Physics Letters, 51(12), 913-915.
Burroughes, J. H., Bradley, D. D. C., Brown, A. R., Marks, R. N., Mackay, K., Friend, R. H., Holmes, A. B. (1990). Light-emitting diodes based on conjugated polymers. Nature, 347, 539-541.
Baldo, M. A., O'brien, D. F., You, Y., Shoustikov, A., Sibley, S., Thompson, M. E., & Forrest, S. R. (1998). Highly efficient phosphorescent emission from organic electroluminescent devices. Nature, 395, 151-154.
Baldo, M. A., O’brien, D. F., Thompson, M. E., Forrest, S. R. (1999). Excitonic singlet-triplet ratio in a semiconducting organic thin film. Physical Review B, 60, 14422.
Suzuki, H., Hoshino, S. (1996). Effects of doping dyes on the electroluminescent characteristics of multilayer organic light‐emitting diodes. Journal of Applied Physics, 79, 8816-8822.
Uchida, M., Adachi, C., Koyama, T., Taniguchi, Y. (1999). Charge carrier trapping effect by luminescent dopant molecules in single-layer organic light emitting diodes. Journal of Applied Physics, 86, 1680-1687.
Lamansky, S., Kwong, R. C., Nugent, M., Djurovich, P. I., Thompson, M. E. (2001). Molecularly doped polymer light emitting diodes utilizing phosphorescent Pt (II) and Ir (III) dopants. Organic Electronics, 2, 53-62.
Lamansky, S., Djurovich, P. I., Abdel-Razzaq, F., Garon, S., Murphy, D. L., & Thompson, M. E. (2002). Cyclometalated Ir complexes in polymer organic light-emitting devices. Journal of Applied Physics, 92, 1570-1575.
He, G., Li, Y., Liu, J., Yang, Y. (2002). Enhanced electroluminescence using polystyrene as a matrix. Applied Physics Letters, 80, 4247-4249.
Ishida, T., Kobayashi, H., Nakato, Y. (1993). Structures and properties of electron‐beam‐evaporated indium tin oxide films as studied by X‐ray photoelectron spectroscopy and work‐function measurements. Journal of Applied Physics, 73(9), 4344-4350.
Kim, J. S., Granström, M., Friend, R. H., Johansson, N., Salaneck, W. R., Daik, R. Cacialli, F. (1998). Indium–tin oxide treatments for single-and double-layer polymeric light-emitting diodes: The relation between the anode physical, chemical, and morphological properties and the device performance. Journal of Applied Physics, 84(12), 6859-6870.
So, S. K., Choi, W. K., Cheng, C. H., Leung, L. M., Kwong, C. F. (1999). Surface preparation and characterization of indium tin oxide substrates for organic electroluminescent devices. Applied Physics A: Materials Science & Processing, 68(4), 447-450.
Mason, M. G., Hung, L. S., Tang, C. W., Lee, S. T., Wong, K. W., Wang, M. (1999). Characterization of treated indium–tin–oxide surfaces used in electroluminescent devices. Journal of Applied Physics, 86(3), 1688-1692.
Van Slyke, S. A., Chen, C. H., Tang, C. W. (1996). Organic electroluminescent devices with improved stability. Applied Physics Letters, 69(15), 2160-2162.
Hsu, C. M., Wu, W. T. (2004). Improved characteristics of organic light-emitting devices by surface modification of nickel-doped indium tin oxide anode. Applied Physics Letters, 85(5).
Borsenberger, P. M., Pautmeier, L., Richert, R., Bässler, H. (1991). Hole transport in 1, 1‐bis (di‐4‐tolylaminophenyl) cyclohexane. The Journal of Chemical Physics, 94(12), 8276-8281.
Kido, J., Ohtaki, C., Hongawa, K., Okuyama, K., Nagai, K. (1993). 1, 2, 4-triazole derivative as an electron transport layer in organic electroluminescent devices. Japanese Journal of Applied Physics, 32(7A), L917.
Xiao, L., Su, S. J., Agata, Y., Lan, H., Kido, J. (2009). Nearly 100% internal quantum efficiency in an organic blue‐light electrophosphorescent device using a weak wlectron transporting material with a wide energy gap. Advanced Materials, 21(12), 1271-1274.
Su, S. J., Gonmori, E., Sasabe, H., Kido, J. (2008). Highly efficient organic blue‐and white‐light‐emitting devices having a carrier‐and exciton‐confining structure for reduced efficiency roll‐off. Advanced Materials, 20(21), 4189-4194.
Adachi, C., Kwong, R. C., Djurovich, P., Adamovich, V., Baldo, M. A., Thompson, M. E., Forrest, S. R. (2001). Endothermic energy transfer: A mechanism for generating very efficient high-energy phosphorescent emission in organic materials. Applied Physics Letters, 79(13), 2082-2084.
Stolka, M., Yanus, J. F., Pai, D. M. (1984). Hole transport in solid solutions of a diamine in polycarbonate. The Journal of Physical Chemistry, 88(20), 4707-4714.
Gong, X., Robinson, M. R., Ostrowski, J. C., Moses, D., Bazan, G. C., Heeger, A. J. (2002). High-efficiency polymer-based electrophosphorescent devices. Advanced Materials, 14(8), 581-585.
Adachi, C., Kwong, R. C., Djurovich, P., Adamovich, V., Baldo, M. A., Thompson, M. E., Forrest, S. R. (2001). Endothermic energy transfer: A mechanism for generating very efficient high-energy phosphorescent emission in organic materials. Applied Physics Letters, 79(13), 2082-2084.
Adamovich, V., Brooks, J., Tamayo, A., Alexander, A. M., Djurovich, P. I., D'Andrade, B. W., Thompson, M. E. (2002). High efficiency single dopant white electrophosphorescent light emitting diodes. New Journal of Chemistry, 26(9), 1171-1178.
Holmes, R. J., Forrest, S. R., Tung, Y. J., Kwong, R. C., Brown, J. J., Garon, S., Thompson, M. E. (2003). Blue organic electrophosphorescence using exothermic host-guest energy transfer. Applied Physics Letters, 82(15), 2422-2424.
Lee, C. W., & Lee, J. Y. (2013). Above 30% external quantum efficiency in blue phosphorescent organic light‐emitting diodes using pyrido [2, 3‐b] indole derivatives as host materials. Advanced Materials, 25(38), 5450-5454.
Udagawa, K., Sasabe, H., Cai, C., Kido, J. (2014). Low‐driving‐voltage blue phosphorescent organic light‐emitting devices with external quantum efficiency of 30%. Advanced Materials, 26(29), 5062-5066.
Seino, Y., Sasabe, H., Pu, Y. J., Kido, J. (2014). High‐performance blue phosphorescent OLEDs using energy transfer from exciplex. Advanced Materials, 26(10), 1612-1616.
Lee, J. H., Cheng, S. H., Yoo, S. J., Shin, H., Chang, J. H., Wu, C. I., Kim, J. J. (2015). An exciplex forming host for highly efficient blue organic light emitting diodes with low driving voltage. Advanced Functional Materials, 25(3), 361-366.
Shin, H., Lee, J. H., Moon, C. K., Huh, J. S., Sim, B., Kim, J. J. (2016). Sky‐blue phosphorescent OLEDs with 34.1% external quantum efficiency using a low refractive index electron transporting layer. Advanced Materials.
陳信仁，利用咔唑衍生物為母體之高效率藍綠磷光有機發光二極體，元智大學，碩士論文，民國102年
洪御翔，高外部量子效率之藍色磷光有機發光二極體，元智大學，碩士論文，民國104年
Perumal, A., Lüssem, B., Leo, K. (2012). High brightness alternating current electroluminescence with organic light emitting material. Applied Physics Letters, 100(10), 103307.
Fröbel, M., Perumal, A., Schwab, T., Gather, M. C., Lüssem, B., Leo, K. (2013). Enhancing the efficiency of alternating current driven organic light-emitting devices by optimizing the operation frequency. Organic Electronics, 14(3), 809-813.
Fröbel, M., Hofmann, S., Leo, K., Gather, M. C. (2014). Optimizing the internal electric field distribution of alternating current driven organic light-emitting devices for a reduced operating voltage. Applied Physics Letters, 104(7), 071105.
Perumal, A., Lüssem, B., Leo, K. (2012). Ultra-bright alternating current organic electroluminescence. Organic Electronics, 13(9), 1589-1593.
Fröbel, M., Perumal, A., Schwab, T., Fuchs, C., Leo, K., Gather, M. C. (2013). White light emission from alternating current organic light‐emitting devices using high frequency color‐mixing. Physica Status Solidi (a), 210(11), 2439-2444.
Liu, S. Y., Chang, J. H., Wu, I. W., Wu, C. I. (2014). Alternating current driven organic light emitting diodes using lithium fluoride insulating layers. Scientific reports, 4.
Su, S. J., Chiba, T., Takeda, T., Kido, J. (2008). Pyridine‐containing triphenylbenzene derivatives with high electron mobility for highly efficient phosphorescent OLEDs. Advanced Materials, 20(11), 2125-2130.