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研究生： 林鈺珺
Lin, Yu-Chun
論文名稱： 聚乙烯亞胺金屬陰極於高分子發光二極體
Polyethyleneimine/metal functionalized cathode in efficient polymer light-emitting diodes
指導教授： 郭宗枋
Guo, Tzung-Fang
學位類別： 碩士
Master
系所名稱： 理學院 - 光電科學與工程學系
Department of Photonics
論文出版年： 2012
畢業學年度： 100
語文別： 中文
論文頁數： 87
中文關鍵詞： 高分子發光二極體 、聚乙烯亞胺 、電子注入層
外文關鍵詞： polymer light emitting diode, polyethyleneimine, electron injection layer
相關次數： 點閱：80  下載：4 
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    • 本研究成功使用旋轉塗佈法成膜聚乙烯亞胺 (polyethyleneimine, PEI) 做為電子注入層，並搭配各種高功函數金屬 (鋁、銀、金) 做為陰極，應用在以黃光材料PDY-132作為主動層的高分子發光二極體中，使元件能在低操作電壓時誘發電子載子注入到有機發光層內，增加發光效率。
    使用聚乙烯亞胺增加電子注入提升效率主要的主要機制有：1.聚乙烯亞胺能在和金屬的界面產生偶極矩進而有效改變真空能階，使注入的位障降低。2. 聚乙烯亞胺可以在發光層和金屬間做為一個緩衝層，有效防止蒸鍍金屬時，金屬擴散進入主動層使激子 (exciton) 由非放光形式釋放能量。
    搭配Al金屬的元件，效率從0.08 cd/A提升到5.68 cd/A；搭配Ag金屬時，效率從0.15 cd/A提升到6.79 cd/A；搭配Au金屬時，從元件無法運作到效率4.67 cd/A，證明加入聚乙烯亞胺做為電子注入層後，確實能適用於各種金屬來降低電子注入的位障。如此一來既可以克服低功函數在一般大氣環境下的不穩定，也能因著對於金屬沒有選擇性的特性使材料發展可能性更廣泛。

    In this work, we report the highly efficient yellow polymer light-emitting diodes (PLEDs) achieved by introducing a soluble polyethyleneimine (PEI) between the high work-function cathodes and the polymer emitting layer (PDY-132). It reduces the barrier height between emitting layer and cathode, and therefore improves device performance.
    The mechanisms of polyethyleneimine as electron injection layer (EIL) to increase the electron injection are 1. Interfacial dipole between Polyethylenimine/metal can change the vacuum energy level thus reduces the barrier height for electron injection. 2. Polyethylenimine as a buffer layer between the emitting layer and the metal can prevent the diffusion of metal particles into the active layer when (thermally) depositing metal and also suppress the formation of metal-induced EL quenching sites in the emitting layer.
    With the devices of Al as cathode, the efficiency uplifts from 0.08 cd/A to 5.68 cd/A; with Ag cathode, the efficiency from 0.15 cd/A up to 6.79 cd/A; and with Au cathode, device improves from not-workingto 4.67 cd/A. The result proves that by adding polyethyleneimine as an electron injection layer, the material can apply to all kinds of metal to reduce the electron injection barrier. Therefore, PEI as an EIL can not only overcome the instability of the low work function metal in the atmosphere, but also have more potential develop because of selective characteristics of the material.

    摘要 I Abstract II 誌謝 III 目錄 IV 表目錄 VII 圖目錄 VIII 第一章 序論 1 1-1 前言 1 1-2 有機電激發光元件的發展 2 1-2-1 小分子與高分子 2 1-2-2 有機電激發光顯示器 3 1-2-3 OLED發展現況 5 1-3 研究動機與大綱 6 1-3-1 研究動機 6 1-3-2 研究大綱 7 第二章 有機發光二極體作用機制與陰極注入特性改善之回顧 12 2-1 高分子電激發光二極體之發光原理 12 2-1-1 有機材料的特性 12 2-1-2 討論有機與無機電激發光的機制 12 2-1-3 歐姆接觸與蕭基接觸 13 2-1-4 高分子電激發光二極體結構 14 2-2 高分子電激發光二極體運作機制探討 15 2-3 高分子電激發光二極體陰極注入特性改善之回顧 16 2-3-1 電子注入層之作用機制與特性 16 2-3-2 電子注入層現今存在的問題 19 2-4 結論 19 第三章 實驗方法與步驟 25 3-1 ITO基板處裡 25 3-1-1 圖案化 25 3-1-2 ITO基板清潔與表面處理 26 3-2 高分子發光二極體元件製作 27 3-2-1 電洞傳輸層 27 3-2-2 發光層 27 3-2-3 電子注入層 28 3-2-4 蒸鍍電極 28 3-3 元件特性量測 28 3-3-1 電流-亮度-電壓 (I-L-V) 特性曲線量測 28 3-3-2 光伏量測法 29 3-3-3 阻抗量測 29 3-3-4 熱重分析儀 29 3-3-5 X光光電子能譜儀 30 3-3-6 紫外光光電子能譜儀 30 3-3-7 光致發光 31 3-4 結論 31 第四章 電性分析聚乙烯亞胺奈米層於有機高分子發光元件 36 4-1 前言 36 4-2 探討聚乙烯亞胺奈米層不同成膜條件下的變化 37 4-2-1 聚乙烯亞胺奈米層使用熱蒸鍍製程 37 4-2-2 聚乙烯亞胺TGA分析與蒸鍍溫度比較 37 4-2-3 聚乙烯亞胺奈米層使用濕式製程 38 4-2-4 不同分子量聚乙烯亞胺奈米層之影響 39 4-3 電性探討聚乙烯亞胺電子注入層的作用 40 4-3-1 交流阻抗頻譜分析 40 4-3-2 聚乙烯亞胺奈米層搭配鋁電極之陰極結構與其他陰極結構之電子注入能力比較 41 4-4 實驗觀察聚乙烯亞胺奈米層與金屬之相依性探討 42 4-4-1 聚乙烯亞胺奈米層搭配各種金屬的電性分析 42 4-4-2 聚乙烯亞胺奈米層相較於聚乙二醇二甲醚的突破 43 4-5 結論 45 第五章 聚乙烯亞胺奈米層於有機高分子發光元件陰極結構之運作機制探討 62 5-1 前言 62 5-2 聚乙烯亞胺奈米層與金屬間化學反應與電子注入提升之關聯 63 5-2-1 實驗探討聚乙烯亞胺奈米層與金屬間化學反應 63 5-3 聚乙烯亞胺奈米層產生偶極效應與電子注入提升之關聯 64 5-3-1 實驗觀察塗佈聚乙烯亞胺奈米層在UPS上的變化 65 5-3-2 實驗探討聚乙烯亞胺奈米層與金屬界面偶極現象 65 5-4 聚乙烯亞胺奈米層做為阻擋層防止電極擴散之影響 66 5-4-1 實驗探討聚乙烯亞胺奈米層對於主動層保護的現象 66 5-5 壽命及儲存時間之測試 67 5-6 結論 68 第六章 總結與未來工作建議 81 6-1 總結 81 6-2 未來工作建議 82 參考文獻 83 自述 87 表目錄 表1-1 各種顯示技術的特性比較。 8 表1-2 2012年後顯示器的應用發展規劃。 11 表4-1 PEI搭配不同金屬的的整體比較。 60 圖目錄 圖1-1 電激發光元件(本實驗室製作)。8 圖1-2 2012 LG在CES展示的55吋OLED TV採用了紅、藍、綠、白4-Color pixel。9 圖1-3 OLED技術暨產品發展藍圖。9 圖1-4 小分子系與高分子系代表性的發光材料。10 圖1-5 鄧青雲博士提出疊層式的元件構造，大幅增加放光效率。10 圖2-1 有機半導體載子傳輸模式。20 圖2-2 無機半導體載子傳輸模式。20 圖2-3 金屬與半導體接面能帶示意圖 (a) ΦM › ΦS (b) ΦM ‹ ΦS。21 圖2-4 歐姆接面與蕭基接面電流與電壓關係圖。21 圖2-5 電激發光原理示意圖 (a) 電子電洞注入 (b) 帶電載子傳輸 (c) 帶電載子再結合。22 圖2-6 OLED螢光、磷光放光路徑示意圖。23 圖2-7 Fowler-Nordheim穿隧模型。23 圖2-8 不同極性方向的所產生的偶極效應。24 圖3-1 ITO基板圖案化前後示意圖。32 圖3-2 旋轉塗佈成膜示意圖。32 圖3-3 PLED元件結構示意圖。33 圖3-4 實驗中所使用的有機材料結構式。33 圖3-5 元件電及mask示意圖及蒸鍍系統側視圖。34 圖3-6 XPS實驗裝置示意圖。34 圖3-7 XPS 原理示意簡圖及能量示意簡圖。35 圖3-8 PL量測方法示意簡圖。35 圖4-1 PLED基本元件結構示意圖。46 圖4-2 Ca與Al陰極注入位障示意圖。46 圖4-3 蒸鍍不同金屬陰極於發光層 PDY-132之高分子發光二極體元件 (a) I-L-V curve分析圖，(b) L-E curve分析圖 (○)ITO/PEDOT/PDY-132/Al；(□) ITO/PEDOT/PDY-132/Ca/Al。47 圖4-4 高分子發光二極體元件結構圖 (於發光層與鋁金屬間蒸鍍4.5 nm的電子注入層)。48 圖4-5 蒸鍍PEI與PEGDE的奈米層於高分子發光二極體元件的I-L-V curve及LE curve (○)ITO/PEDOT/PDY-132/PEGDE/Al； (□)ITO/PEDOT/PDY-132/PEI/Al。48 圖4-6 PEGDE與PEI的TGA和蒸鍍溫度比較分析圖。49 圖4-7 PEI使用石英矸鍋量測蒸鍍溫度。49 圖4-8 分子量2500的PEI在濃度0.04 %時不同轉速的結果(a) I-L-V curve分析圖，(b) LE curve分析圖 。(○)ITO/PEDOT/PDY-132/PEI (0.04 %, 2000 rpm)/Al； (□)ITO/PEDOT/PDY-132/PEI (0.04 %, 4000 rpm)/Al；(◇)ITO/PEDOT/PDY-132/PEI (0.04 %, 6000 rpm)/Al。50 圖4-9 分子量2500的PEI在濃度0.08 %時不同轉速的結果(a) I-L-V curve分析圖，(b) LE curve分析圖 。(○)ITO/PEDOT/PDY-132/PEI (0.08 %, 6000 rpm)/Al； (□)ITO/PEDOT/PDY-132/PEI (0.08 %, 7000 rpm)/Al。51 圖4-10 分子量25000的PEI在濃度0.04 %時不同轉速的結果(a) I-L-V curve分析圖，(b) LE curve分析圖 。(○)ITO/PEDOT/PDY-132/PEI (0.04 %, 2000 rpm)/Al； (□)ITO/PEDOT/PDY-132/PEI (0.04 %, 4000 rpm)/Al。(◇)ITO/PEDOT/PDY-132/PEI (0.04 %, 6000 rpm)/Al。52 圖4-11 分子量25000的PEI在濃度0.08 %時不同轉速的結果(a) I-L-V curve分析圖，(b) LE curve分析圖 。(○)ITO/PEDOT/PDY-132/PEI (0.04 %, 6000 rpm)/Al； (□)ITO/PEDOT/PDY-132/PEI (0.04 %, 7000 rpm)/Al。(◇)ITO/PEDOT/PDY-132/PEI (0.04 %, 8000 rpm)/Al。53 圖4-12 分子量25000的PEI不同成膜條件下的Voc比較。54 圖4-13 不同分子量的PEI的Voc比較。54 圖4-14 從Nyquist plot觀察PEI對元件整體阻抗的影響。55 圖4-15 使用不同陰極的PDY-132高分子發光二極體的比較(a) I-L-V curve分析圖，(b) LE curve分析圖 (插入圖為EL光譜)。(○)ITO/PEDOT/PDY-132/Al； (□)ITO/PEDOT/PDY-132/Ca/Al。(◇)ITO/PEDOT/PDY-132/PEI (0.08 %, 7000 rpm)/Al。56 圖4-16 使用不同陰極的PDY-132高分子發光二極體的Voc比較。57 圖4-17 使用不同陰極的PDY-132高分子發光二極體注入位障與陰陽極功函數差的相對關係示意圖。57 圖4-18 PEI搭配Al金屬的I-L-V分析圖。58 圖4-19 PEI搭配Ag金屬的I-L-V分析圖。58 圖4-20 PEI搭配Au金屬的I-L-V分析圖。59 圖4-21 PEI搭配不同金屬的LE分析圖。59 圖4-22 PEGDE搭配不同金屬的Voc比較圖。60 圖4-23 PEI搭配不同金屬的Voc比較圖。61 圖5-1 加入PEI奈米層後可能幫助電子注入的機制示意圖。69 圖5-2 XPS對於C-1s軌域解析PEI薄膜的組成。70 圖5-3 PEI上蒸鍍Al和Ag的XPS (C-1s)圖譜。70 圖5-4 XPS對於C-1s軌域解析PEI/Al薄膜的組成。71 圖5-5 XPS對於C-1s軌域解析PEGDE/Al薄膜的組成。71 圖5-6 PEI/Al和Al陰極的I-L-V curve分析圖。72 圖5-7 PEGDE/Al和Al陰極的I-L-V curve分析圖。72 圖5-8 XPS對於C-1s軌域解析PEI/Ag薄膜的組成。73 圖5-9 XPS對於C-1s軌域解析PEGDE/Ag薄膜的組成。73 圖5-10 PEI/Ag和Ag元件的Voc比較。74 圖5-11 PEGDE/Ag和Ag的元件Voc比較。74 圖5-12 在發光層與金屬間加入PEI的cot-off region比較 (a) 搭配Al金屬 (b) 搭配Ag金屬。75 圖5-13 純PEI與鍍上金屬的UPS比較(a) HOMO region (b) cut-off region。76 圖5-14 PL量測的元件結構比較。77 圖5-15 PL量測不同金屬厚度對主動層的影響。77 圖5-16 PL量測結果圖。(○) ITO/ PDY-132；(□) ITO/ PDY-132/ PEI/ Al；(◇) ITO /PDY-132/ Al。78 圖5-17 PL量測結果圖。(○) ITO/ PDY-132；(□) ITO/ PDY-132/ PEGDE/ Al。(◇) ITO /PDY-132/ Al。78 圖5-18 PEI/Al陰極元件連續施加1 mA的壽命測試。79 圖5-19不同陰極結構於大氣下的儲存時間測試。79 圖5-20 PEI機制示意圖。80

    [1]M. Pope, H. P. Kallmann, and P. Magnante, "Electroluminescence in Organic Crystals," Journal of Materials Chemistry, vol. 38, pp. 2042-2043, 1963.
    [2]C. K. Chiang, C. R. Fincher, Y. W. Park, A. J. Heeger, H. Shirakawa, E. J. Louis, S. C. Gau, and A. G. Macdiarmid, "Electrical-Conductivity in Doped Polyacetylene," Physical Review Letters, vol. 39, pp. 1098-1101, 1977.
    [3]C. W. Tang and S. A. Vanslyke, "Organic Electroluminescent Diodes," Applied Physics Letters, vol. 51, pp. 913-915, 1987.
    [4]R. H. Partridge, "Electroluminescence from polyvinylcarbazole films: 1. Carbazole cations," Polymer, vol. 24, pp. 733-738, 1984.
    [5]J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Marks, K. Mackay, R. H. Friend, P. L. Burns, and A. B. Holmes, "Light-Emitting-Diodes Based on Conjugated Polymers," Nature, vol. 347, pp. 539-541, 1990.
    [6]D. Braun and A. J. Heeger, "Visible-Light Emission from Semiconducting Polymer Diodes," Applied Physics Letters, vol. 58, pp. 1982-1984, 1991.
    [7]Y. Cao, G. Yu, I. D. Parker, and A. J. Heeger, "Ultrathin layer alkaline earth metals as stable electron-injecting electrodes for polymer light emitting diodes," Journal of Applied Physics, vol. 88, pp. 3618-3623, 2000.
    [8]H. H. P. Gommans, A. W. D. van der Gon, G. G. Andersson, L. J. van IJzendoorn, R. M. T. Pijper, and H. H. Brongersma, "Interface formation in K doped poly(dialkoxy-p-phenylene vinylene) light-emitting diodes," Journal of Applied Physics, vol. 94, pp. 5756-5762, 2003.
    [9]A. Nakamura, T. Tada, M. Mizukami, and S. Yagyu, "Efficient electrophosphorescent polymer light-emitting devices using a Cs/Al cathode," Applied Physics Letters, vol. 84, pp. 130-132, 2004.
    [10]L. S. Hung, C. W. Tang, and M. G. Mason, "Enhanced electron injection in organic electroluminescence devices using an Al/LiF electrode," Applied Physics Letters, vol. 70, pp. 152-154, 1997.
    [11]P. Piromreun, H. Oh, Y. L. Shen, G. G. Malliaras, J. C. Scott, and P. J. Brock, "Role of CsF on electron injection into a conjugated polymer," Applied Physics Letters, vol. 77, pp. 2403-2405, 2000.
    [12]J. S. Huang, Z. Xu, and Y. Yang, "Low-work-function surface formed by solution-processed and thermally deposited nanoscale layers of cesium carbonate," Advanced Functional Materials, vol. 17, pp. 1966-1973, 2007.
    [13]T. M. Brown, R. H. Friend, I. S. Millard, D. J. Lacey, T. Butler, J. H. Burroughes, and F. Cacialli, "Electronic line-up in light-emitting diodes with alkali-halide/metal cathodes," Journal of Applied Physics, vol. 93, pp. 6159-6172, 2003.
    [14]H. J. Bolink, E. Coronado, J. Orozco, and M. Sessolo, "Efficient Polymer Light-Emitting Diode Using Air-Stable Metal Oxides as Electrodes," Advanced Materials, vol. 21, pp. 79-82, 2009.
    [15]Q. F. Xu, J. Y. Ouyang, Y. Yang, T. Ito, and J. Kido, "Ultrahigh efficiency green polymer light-emitting diodes by nanoscale interface modification," Applied Physics Letters, vol. 83, pp. 4695-4697, 2003.
    [16]T. F. Guo, F. S. Yang, Z. J. Tsai, T. C. Wen, S. N. Hsieh, and Y. S. Fu, "High-performance polymer light-emitting diodes utilizing modified Al cathode," Applied Physics Letters, vol. 87,pp. 13504, 2005.
    [17]T. F. Guo, F. S. Yang, Z. J. Tsai, T. C. Wen, S. N. Hsieh, Y. S. Fu, and C. T. Chung, "Organic oxide/Al composite cathode in efficient polymer light-emitting diodes," Applied Physics Letters, vol. 88, pp. 113501, 2006.
    [18]T. F. Guo, F. S. Yang, Z. J. Tsai, G. W. Feng, T. C. Wen, S. N. Hsieh, C. T. Chung, and C. I. Wu, "High-brightness top-emissive polymer light-emitting diodes utilizing organic oxide/Al/Ag composite cathode," Applied Physics Letters, vol. 89, pp. 51103, 2006.
    [19]T. F. Guo, F. S. Yang, Z. J. Tsai, T. C. Wen, C. I. Wu, and C. T. Chung, "Organic oxide/Al composite cathode in small molecular organic light-emitting diodes," Applied Physics Letters, vol. 89, pp. 53507, 2006.
    [20]T. H. Lee, J. C. A. Huang, G. L. Pakhomov, T. F. Guo, T. C. Wen, Y. S. Huang, C. C. Tsou, C. T. Chung, Y. C. Lin, and Y. J. Hsu, "Organic-Oxide Cathode Buffer Layer in Fabricating High-Performance Polymer Light-Emitting Diodes," Advanced Functional Materials, vol. 18, pp. 3036-3042, 2008.
    [21]J. H. Park, O. O. Park, J. W. Yu, J. K. Kim, and Y. C. Kim, "Effect of polymer-insulating nanolayers on electron injection in polymer light-emitting diodes," Applied Physics Letters, vol. 84, pp. 1783-1785, 2004.
    [22]Y. H. Niu, A. K. Y. Jen, and C. F. Shu, "High-efficiency polymer light-emitting diodes using neutral surfactant modified aluminum cathode," Journal of Physical Chemistry B, vol. 110, pp. 6010-6014, 2006.
    [23]X. Y. Deng, W. M. Lau, K. Y. Wong, K. H. Low, H. F. Chow, and Y. Cao, "High efficiency low operating voltage polymer light-emitting diodes with aluminum cathode," Applied Physics Letters, vol. 84, pp. 3522-3524, 2004.
    [24]F. Huang, Y. H. Niu, Y. Zhang, J. W. Ka, M. S. Liu, and A. K. Y. Jen, "A conjugated, neutral surfactant as electron-injection material for high-efficiency polymer light-emitting diodes," Advanced Materials, vol. 19, pp. 2010-2014, 2007.
    [25]F. Huang, Y. Zhang, M. S. Liu, and A. K. Y. Jen, "Electron-Rich Alcohol-Soluble Neutral Conjugated Polymers as Highly Efficient Electron-Injecting Materials for Polymer Light-Emitting Diodes," Advanced Functional Materials, vol. 19, pp. 2457-2466, 2009.
    [26]H. B. Wu, F. Huang, Y. Q. Mo, W. Yang, D. L. Wang, J. B. Peng, and Y. Cao, "Efficient electron injection from a bilayer cathode consisting of aluminum and alcohol-/water-soluble conjugated polymers," Advanced Materials, vol. 16, pp. 1826-1830, 2004.
    [27]F. Huang, H. B. Wu, D. Wang, W. Yang, and Y. Cao, "Novel electroluminescent conjugated polyelectrolytes based on polyfluorene," Chemistry of Materials, vol. 16, pp. 708-716, 2004.
    [28]F. Huang, H. B. Wu, and Y. Cao, "Water/alcohol soluble conjugated polymers as highly efficient electron transporting/injection layer in optoelectronic devices," Chemical Society Reviews, vol. 39, pp. 2500-2521, 2010.
    [29]Y. Zhang, F. Huang, Y. Chi, and A. K. Y. Jen, "Highly efficient white polymer light-emitting diodes based on nanometer-scale control of the electron injection layer morphology through solvent processing," Advanced Materials, vol. 20, pp. 1565-1570, 2008.
    [30]C. I. Wu, C. T. Lin, Y. H. Chen, M. H. Chen, Y. J. Lu, and C. C. Wu, "Electronic structures and electron-injection mechanisms of cesium-carbonate- incorporated cathode structures for organic light-emitting devices," Applied Physics Letters, vol. 88, pp. 152104, 2006.
    [31]Y. Li, D. Q. Zhang, L. Duan, R. Zhang, L. D. Wang, and Y. Qiu, "Elucidation of the electron injection mechanism of evaporated cesium carbonate cathode interlayer for organic light-emitting diodes," Applied Physics Letters, vol. 90, pp. 12119, 2007.
    [32]S. E. Shaheen, G. E. Jabbour, M. M. Morrell, Y. Kawabe, B. Kippelen, N. Peyghambarian, M. F. Nabor, R. Schlaf, E. A. Mash, and N. R. Armstrong, "Bright blue organic light-emitting diode with improved color purity using a LiF/Al cathode," Journal of Applied Physics, vol. 84, pp. 2324-2327, 1998.
    [33]I. D. Parker, "Carrier Tunneling and Device Characteristics in Polymer Light-Emitting-Diodes," Journal of Applied Physics, vol. 75, pp. 1656-1666, 1994.
    [34]H. Heil, J. Steiger, S. Karg, M. Gastel, H. Ortner, H. von Seggern, and M. Stossel, "Mechanisms of injection enhancement in organic light-emitting diodes through an Al/LiF electrode," Journal of Applied Physics, vol. 89, pp. 420-424, 2001.
    [35]T. Mori, H. Fujikawa, S. Tokito, and Y. Taga, "Electronic structure of 8-hydroxyquinoline aluminum/LiF/Al interface for organic electroluminescent device studied by ultraviolet photoelectron spectroscopy," Applied Physics Letters, vol. 73, pp. 2763-2765, 1998.
    [36]J. H. Seo and T. Q. Nguyen, "Electronic properties of conjugated polyelectrolyte thin films," Journal of the American Chemical Society, vol. 130, pp. 10042-10043, 2008.
    [37]M. Stoessel, G. Wittmann, J. Staudigel, F. Steuber, J. Blassing, W. Roth, H. Klausmann, W. Rogler, J. Simmerer, A. Winnacker, M. Inbasekaran, and E. P. Woo, "Cathode-induced luminescence quenching in polyfluorenes," Journal of Applied Physics, vol. 87, pp. 4467-4475, 2000.
    [38]V. Choong, Y. Park, Y. Gao, T. Wehrmeister, K. Mullen, B. R. Hsieh, and C. W. Tang, "Dramatic photoluminescence quenching of phenylene vinylene oligomer thin films upon submonolayer Ca deposition," Applied Physics Letters, vol. 69, pp. 1492-1494, 996.
    [39]Y. H. Niu, H. Ma, Q. M. Xu, and A. K. Y. Jen, "High-efficiency light-emitting diodes using neutral surfactants and aluminum cathode," Applied Physics Letters, vol. 86, pp. 83504, 2005.

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