臺灣博碩士論文加值系統

本實驗使用poly-p-phenylenebenzobisoxazole (PBO)的雜環芳香族全共軛硬桿式高分子作為主要的光電作用層，在其中混摻不同濃度的奈米碳球[6,6]-phenyl-C61-butyric acid methyl ester (PC61BM)與酯化奈米碳管multi-wall carbon nanotube-C18 (MWCNT- C18)。並加入導電性高分子材料poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS)做為電洞傳輸層，陰極及陽極分別使用鋁(Al)及氧化銦錫(indium tin oxide，ITO)，來製作高分子發光二極體，形成ITO/PEDOT:PSS/ PBO/Al雙層結構，以進行電性和光性的量測。
由實驗可知，當利用旋轉塗佈速度不同來控制PEDOT:PSS膜厚，改變元件的光歷程(optical path)。隨著塗佈速度上升，PEDOT:PSS的膜厚變薄，元件的最強放光波長(λmax)有藍位移的現象；而以較高轉速重複塗佈PEDOT:PSS來控制膜厚時，隨著塗佈次數增加，最強放光波長(λmax)有紅位移的現象。不論用哪一種方法製做薄膜，當PEDOT:PSS的膜厚接近時， 其元件電致光光譜非常接近。
而在PBO中混摻奈米碳球(PC61BM)與酯化奈米碳管(MWCNT-C18)皆可使高分子發光二極體元件的注入電流與發光亮度增加。由平行膜面直流導電度(σ∥)量測可以發現，隨著混摻濃度的提高，薄膜的導電度有上升的現象。而因為PC61BM與MWCNT-C18迥異的長寬比(aspect ratio)，造成逾滲濃度(percolation threshold concentration)差異很大，MWCNT-C18在較低的混摻濃度即可以達到較好的導電度。

Polymer light emitting diodes (PLED) were using a heterocyclic aromatic rigid-rod polymer poly-p-phenylene-benzobisoxazole (PBO) as an opto-electronically active layer; and poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonic acid) (PEDOT:PSS) as a hole transporting layer. Aluminum (Al) and indium tin oxide (ITO) were served as device cathode and anode, respectively. [6,6]-phenyl C61-butyric acid methyl ester (PC61BM) or derivatized multi-wall carbon nano-tube (MWCNT-C18), with great electron transporting ability, was doped into PBO to enhance the performance of PLED devices as well as the thin-film electrical conductivity.
The optical length was changed by using different spin coating speeds and durations. From the research, the λmax of electroluminescence (EL) was blue-shifted as PEDOT:PSS spin coating speed increased for a thinner layer. Once using a higher spin coating speed repeatedly to coat PEDOT:PSS, the λmax of electroluminescence was red-shifted. If the PEDOT:PSS film thicknesses were similar, the EL spectra were almost the same, independent of device processing scheme.
The injection current and EL intensity were enhanced by doping PC61BM or MWCNT- C18. The electric conductivity parallel to film surface (σ∥) was increased as the doping concentration increased. Because of the extremely different aspect ratio, the MWCNT-C18 had a lower percolation threshold concentration. Therefore, at a low MWCNT-C18 doping concentration, the injection current and the EL intensity were enhanced compared with those of PC61BM.

圖目錄 IV
表目錄 VIII
一、緒論 1
1-1 前言 1
1-2 研究動機 2
二、原理與實驗 3
2-1 發光二極體元件結構 3
2-1-1 單層元件結構 3
2-1-2 多層元件結構[5] 4
2-2 發光二極體元件材料 5
2-2-1 陽極(Anode)[6] 5
2-2-2 陰極(Cathode) 6
2-2-3 PBX硬桿式共軛高分子 7
2-2-4 PEDOT:PSS電洞傳輸層 8
2-2-5 PC61BM電子傳輸材料 9
2-2-6 奈米碳管 9
2-3 發光二極體原理 11
2-3-1 載子傳導機制 11
2-3-2 能帶理論(Energy Band Theory) 12
2-3-3 能量釋放原理 14
2-3-4 微腔(Micro-cavity)共振效應 15
2-4 實驗設備 18
2-4-1 手套箱(Glove Box)系統 18
2-4-2 氧電漿(O2 Plasma)清洗機 18
2-4-3 旋轉塗佈機(Spin Coater) 18
2-4-4 真空熱蒸鍍機(Vacuum Thermal Evaporator) 19
2-4-5 電性量測：Keithley® 2400之應用 20
2-4-6 電致光(Electroluminescence，EL)光譜量測 21
2-4-7 導電性量測(Electric Conductivity) / Keithley® 237之應用 22
2-4-8 紫外光-可見光吸收光譜(UV-Vis Absorption Spectrum) [21] 23
2-4-9 掃描式電子顯微鏡(Scanning Electron Microscope，SEM) 25
三、實驗內容 27
3-1 元件的製備 27
3-1-1 高分子溶液配製 27
3-1-2 清洗ITO玻璃 28
3-1-3 旋轉塗佈製備薄膜 30
3-1-4 PBO薄膜乾燥處理 30
3-1-5 熱蒸鍍 30
3-2 元件量測 31
3-2-1 電性量測 31
3-2-2 電致光(EL)光譜 31
3-2-3 四點探針直流電(Four-probe DC)測量法 32
3-2-4 掃描式電子顯微鏡(Scanning Electron Microscope，SEM)量測 32
3-2-5 紫外光-可見光吸收光譜(UV-Vis Absorption Spectrum)量測 33
3-3 多層奈米碳管之化學合成改質[27] 33
3-3-1 多層奈米碳管酸化反應 33
3-3-2 多層奈米碳管酯化反應 34
四、結果與討論 35
4-1 PEDOT:PSS薄膜厚度改變 35
4-2 PBO混摻不同濃度之PC61BM 44
4-3 PBO混摻不同濃度之酯化多層奈米碳管(MWCNT-C18) 49
4-4 PBO混摻MWCNT-C18或PC61BM之平行膜面直流導電度 54
五、結論 66
六、參考文獻 68

1. M. Pope, H. P. Kallmann, and P. Magnante, J. Chem. Phys., 38, 2042 (1963).
2. C. W. Tang and S. A. Van Slyke, Appl. Phys. Lett., 51, 913 (1987).
3. J. H. Burroughes, D. D. C. Bradley, A. R. Brown, R. N. Mackay, R. H. Friend, P. L. Burns, and A. B. Homes, Nature, 347, 539 (1990).
4. 陳金鑫，黃孝文，「有機電激發光材料與元件」，五南圖書出版公司，台灣，2006。
5. J. Shi and C. W. Tang, Appl. Phys. Lett., 70, 1665 (1997).
6. 紀國鐘，鄭晃忠，「液晶顯示器技術手冊」，台灣電子材料與元件協會，台北，2004。
7. L. B. Groenendaal, F. Jonas, D. Freitag, H. Pielartzik, and J. R. Reynolds, Adv. Funct. Mater., 12, 481 (2000).
8. A. D. Pasquier, H. E. Unalan, A. Kanwal, S. Miller, and M. Chhowalla, Appl. Phys. Lett., 87, 203511 (2005).
9. S. Iijima, Nature, 354, 56 (1991).
10. O. Zhou, R. M. Fleming, and D. W. Murphy, Science, 263, 1774 (1994).
11. H. Dai, E. W. Wong, and C. M. Lieber, Science, 272, 523 (1996).
12. T. W. Ebbesen, H. J. Lezec, H. Hiura, J. W. Bennett, H. F. Ghaemi, and T. Thio, Nature, 382, 54 (1996).
13. C. Velasco-Santos, Chem. Mater., 15, 4470 (2003).
14. Y. P. Sun , K. Fu, Y. Lin, and W. Huang, Acc. Chem. Res, 35, 1096 (2002).
15. http://www.seas.upenn.edu/mse/research/nanotubes.html
16. http://www.den.hokudai.ac.jp/rikou/akasaka/homemenu/Chemical%20Illustration/
Carbon/Carbon.html
17. C. Kittel, "Introduction to Solid State Physics," 6th ed., John Wiley & Sons, Singapore, 1986.
18. H. Y. Cheng, "Electrode Modifications of Molecular Light Emitting Diodes, " Master Thesis, National Sun Yat-Sen University (Kaohsiung), 2003.
19. V. Cimrova and D. Neher, J. Appl. Phys., 79(6), 3299 (1996).
20. A. Dodabalapur, L. J. Rothberg, and T. M. Miller, Appl. Phys. Lett., 65, 2308 (1999).
21. S. K. So, W. K. Choi, L. M. Leung, and K. Neyts, Appl. Phys. Lett., 74, 1939 (1999).
22. D. Pavia, G. M. Lampman, and G. S. Kriz，"Introduction to Spectroscopy," Thomson Learning, Boston, 2003.
23. 施敏，「半導體元件物理與製作技術」，國立交通大學出版社，台灣，2003。
24. Y. Shi, J. Liu, and Y. Yang, J. Appl. Phys., 87(9), 4254 (2000).
25. C. C. Wu, "Luminescence of Light Emitting Diodes of Fully Conjugated Heterocyclic Aromatic Rigid-rod Polymer," Ph.D. Thesis, National Sun Yat-Sen Univrsity (Kaohsiung), 2003.
26. H. C. Liao, "Package of Homojunction of Fully Conjugated Heterocyclic Aromatic Rigid-rod Polymer Light Emitting Diodes " Master Thesis, National Sun Yat-Sen Univrsity (Kaohsiung), 2004.
27. R. C. Kwong, M. R. Nugent, L. Michalski, T. Ngo, K. Rajan, Y. J. Tung, M. S. Weaver, T. X. Zhou, M. Hack, M. E. Thompson, S. R. Forrest, and J. J. Brown, Appl. Phys. Lett., 81, 162 (2002).
28. J. S. Lin, "In-situ Chemical Synthesis and Light Emitting Diodes of Non-fully Conjugated Hetrocyclic Aromatic Polymer with Functionalized Multi-wall Carbon Nanotube " Master Thesis, National Sun Yat-Sen University (Kaohsiung), 2008.
29. H. Kim, J. Y. Kim, S. H. Park, and K. Lee, Appl. Phys. Lett., 86, 183502 (2005).
30. J. D. Chirvase, J. Parisi, J. C. Hummelen, and V. Dyaknov, Nanotechnology, 15, 1317 (2004).
31. C. Zhou, S. Wang, Q. Zhuang, and Z. Han, Carbon, 46, 1232 (2008).
32. S. Berson, R. D. Bettignies, S. Bailly, S. Guillerez, and B. Jousselme, Adv. Funct. Mater., 17, 3363 (2007).
33. G. F. Wang, X. M. Tao, W. Chen, R. X. Wang, and A. Yang, J. of Luminescence, 126, 602 (2007).
34. A. W. Musumeci, G. G. Silva, J. W. Liu, W. N. Martens, and E. R. Waclawik, Polymer, 48, 1667 (2007).
35. L. Wang and Z. M. Dang, Appl. Phys. Lett., 87, 042903 (2005).
36. C. W. Nan, Prog. Mater. Sci., 37, 1 (1993).
37. F. Du, J. E. Fischer, and K. I. Winey, Phys. Rev. B, 72, 121404 (2005).
38. J. Y. Yi and G. M. Choi, J. of Electroceramics, 3, 361 (1999).