本論文將聚乙烯吡咯烷酮混摻不同小分子作為電子注入層應用於高分子發光二極體，搭配高功函數鋁作為陰極，製備出高效率的發光元件。

第一部分使用聚乙烯吡咯烷酮(PVP)作為電子注入層可用來修飾陰極界面，降低電子注入能障，並透過混摻溴化四辛基銨(TOAB)讓該層能更均勻地覆蓋在發光層上，並藉由XRD分析，PVP有助於提升TAOB的結晶性，增加電洞阻擋能力，進一步地提升元件的發光效率，其效率遠超過鈣鋁元件。此外，PVP透過混摻苯乙醯胺(2PAD)也能夠增加元件的發光效率。

第二部分將PVP、TOAB、2PAD混合成三成份電子注入層應用於發光元件上，透過混合物實驗設計發現元件的電流密度和亮度之最大趨勢發生在三成份位置上擁有較多2PAD的混合比例，造成在適當的厚度下可讓電子的注入能障被大幅度降低。至於三成份電子注入層於較多TOAB的混合比例下，搭配PVP之良好的成膜特性讓三種材料都能夠在發光層上均勻地成膜，使得元件的發光效率有最大趨勢。

Highly enhanced electron injection is demonstrated with poly(vinylpyrrolidone) (PVP) as an electron injection layer (EIL) in polymer light-emitting diodes (PLEDs).The blend of PVP with tetraoctylammonium bromide (TOAB) or 2-phenylacetamide (2PAD) results in highly improved device characteristics. The devices with PVP+TOAB/Al and PVP+2PAD/Al cathodes respectively show the higher luminance efficiency (11.6 cd/A and 13.0 cd/A) than the device with the Ca/Al cathode (6.2 cd/A) and PVP /Al (9.6 cd/A).

For higher device performances, PVP, TOAB, and 2PAD are mixed as three-component EILs for high efficient PLEDs. Mixture design is used to analyze the effect of different bled ratios on the device characteristics due to simple experiment analyses. By mixture design, using three-component EILs with different blend ratios can control the performances of the devices. The efficiency of the device with more TOAB blend ratio is higher than other and there are higher current density and brightness in the device with more 2PAD ratio.

1. C. W. Tang and S.A. Vanslyke, "Organic Electroluminescent Diodes", Applied Physics Letters, 51, 12, 913-915, (1987)
2. 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, 347, 6293, 539-541, (1990)
3. X. J. Wang, J. M. Zhao, Y. C. Zhou, X. Z. Wang, S. T. Zhang, Y. Q. Zhan, Z. Xu, H. J. Ding, G. Y. Zhong, H. Z. Shi, Z. H. Xiong, Y. Liu, Z. J. Wang, E. G. Obbard, X. M. Ding, W. Huang and X. Y. Hou, "Enhancement of Electron Injection in Organic Light-Emitting Devices Using an Ag/LiF Cathode", Journal of Applied Physics, 95, 7, 3828-3830,(2004)
4. R. H. Friend, R. W. Gymer, A. B. Holmes, J. H. Burroughes, R. N. Marks, C. Taliani, D. D. C. Bradley, D. A. D. Santos, J. L. Bredas, M. Logdlund and W. R. Salaneck, "Electroluminescence in Conjugated Polymers", Nature, 397, 6715, 121-128, (1999)
5. M. Wohlgenannt, K. Tandon, S. Mazumdar, S. Ramasesha and Z. V. Vardeny, "Formation Cross-Sections of Singlet and Triplet Excitons in π-Conjugated Polymers", Nature, 409, 6819, 494-497, (2001)
6. M. Reufer, M. J. Walter, P. G. Lagoudakis, A. B. Hummel, J. S. Kolb, H. G. Roskos, U. Scherf and J. M. Lupton, "Spin-Conserving Carrier Recombination in Conjugated Polymers", Nat Mater, 4, 4, 340-346, (2005)
7. Y. Xu, R. Yang, J. Peng, A. A. Mikhailovsky, Y. Cao, T.-Q. Nguyen and G. C. Bazan, "Solvent Effects on the Architecture and Performance of Polymer White-Light-Emitting Diodes with Conjugated Oligoelectrolyte Electron-Transport Layers", Advanced Materials, 21, 5, 584-588, (2009)
8. C. C. Wu, C. I. Wu, J. C. Sturm and A. Kahn, "Surface Modification of Indium Tin Oxide by Plasma Treatment: An Effective Method to Improve the Efficiency, Brightness, and Reliability of Organic Light Emitting Devices", Applied Physics Letters, 70, 11, 1348-1350, (1997)
9. J. S. Kim, M. Granström, R. H. Friend, N. Johansson, W. R. Salaneck, R. Daik, W. J. Feast and F. Cacialli, "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, (1998)
10. S. K. So, W. K. Choi, C. H. Cheng, L. M. Leung and C. F. Kwong, "Surface Preparation and Characterization of Indium Tin Oxide Substrates for Organic Electroluminescent Devices", Applied Physics a-Materials Science & Processing, 68, 4, 447-450, (1999).
11. I. D. Parker, "Carrier Tunneling and Device Characteristics in Polymer Light- Emitting Diodes", Journal of Applied Physics, 75, 3, 1656-1666, (1994)
12. A. Elschner, F. Bruder, H. W. Heuer, F. Jonas, A. Karbach, S. Kirchmeyer,
S. Thurm and R. Wehrmann, "PEDT/PSS for Efficient Hole-Injection in Hybrid Organic Light-Emitting Diodes", Synthetic Metals, 111, 139-143, (2000)
13. Y. Cao, G. Yu, C. Zhang, R. Menon and A. J. Heeger, "Polymer Light-Emitting Diodes with Polyethylene Dioxythiophene–Polystyrene Sulfonate as the Transparent Anode", Synthetic Metals, 87, 2, 171-174, (1997)
14. T. M. Brown, J. S. Kim, R. H. Friend, F. Cacialli, R. Daik and W. J. Feast,
"Built-In Field Electroabsorption Spectroscopy of Polymer Light-Emitting Diodes Incorporating A Doped Poly(3,4-Ethylene Dioxythiophene) Hole Injection Layer", Applied Physics Letters, 75, 12, 1679-1681, (1999)
15. G. Liu, A. Y. Li, D. An, H. B. Wu, X. H. Zhu, Y. Li, X. R. Miao, W. L. Deng, W. Yang, Y. Cao and J. Roncali, "An Ionic Molecular Glass as Electron Injection Layer for Efficient Polymer Light-Emitting Diode", Macromolecular Rapid Communications, 30, 17, 1484-1491, (2009)
16. Q. Xu, J. Ouyang, Y. Yang, T. Ito and J. Kido, "Ultrahigh Efficiency Green Polymer Light-Emitting Diodes by Nanoscale Interface Modification", Applied Physics Letters, 83, 23, 4695-4697, (2003)
17. Y. H. Niu, H. Ma, Q. Xu and A. K.-Y. Jen, "High-Efficiency Light-Emitting Diodes Using Neutral Surfactants and Aluminum Cathode", Applied Physics Letters, 86, 8, 083504, (2005)
18. T. H. Lee, J. C. A. Huang, G. L. v. 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, 18, 19, 3036-3042, (2008)
19. S. N. Hsieh, S. W. Hsiao, T. Y. Chen, C. Y. Li, C. H. Lee, T. F. Guo, Y. J. Hsu, T. L. Lin, Y. Wei and T. C. Wen, "Self-Assembled Tetraoctylammonium Bromide as An Electron-Injection Layer for Cathode-Independent High-Efficiency Polymer Light-Emitting Diodes", Journal of Materials Chemistry, 21, 24, 8715-8720, (2011)
20. K. W. Tsai, T. F. Guo, A. K.-Y. Jen and T. C. Wen, "Role of Self-Assembled Tetraoctylammonium Bromide on Various Conjugated Polymers in Polymer Light-Emitting Diodes", Journal of Materials Chemistry C, 2, 2, 272-276, (2014)
21. C. H. Wu, C. Y. Chin, T. Y. Chen, T. F. Guo, C. H. Lee, T. L. Lin, A. K.-Y. Jen and T. C. Wen, "Significance of Ions with An Ordered Arrangement for Enhancing the Electron Injection/Extraction in Polymer Optoelectronic Devices", Journal of Materials Chemistry C, 2, 24, 4805-4811, (2014)
22. 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, 88, 15, 152104, (2006)
23. 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, 90, 1, 012119, (2007)
24. J. 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, 17, 12, 1966-1973, (2007)
25. G. E. Jabbour, Y. Kawabe, S. E. Shaheen, J. F. Wang, M. M. Morrell, B. Kippelen and N. Peyghambarian, "Highly Efficient and Bright Organic Electroluminescent Devices with An Aluminum Cathode", Applied Physics Letters, (1997) , 71, 13, 1762-1764, (1997)
26. H. Heil, J. Steiger, S. Karg, M. Gastel, H. Ortner, H. von Seggern and M. Stößel, "Mechanisms of Injection Enhancement in Organic Light-Emitting Diodes Through An Al/Lif Electrode", Journal of Applied Physics, 89, 1, 420-424, (2001)
27. 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, 84, 4, 2324-2327, (1998)
28. 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, 73, 19, 2763-2765, (1998)
29. H. Siemund, F. Bröcker and H. Göbel, "Enhancing the Electron Injection in Polymer Light-Emitting Diodes Using A Sodium Stearate/Aluminum Bilayer Cathode", Organic Electronics, 14, 1, 335-343, (2013)
30. A. C. Arias, J. D. MacKenzie, I. McCulloch, J. Rivnay and A. Salleo, "Materials and Applications for Large Area Electronics: Solution-Based Approaches", Chemical Reviews, 110, 1, 3-24, (2010)
31. Q. Xu, J. Ouyang, Y. Yang, T. Ito and J. Kido, "Ultrahigh Efficiency Green Polymer Light-Emitting Diodes by Nanoscale Interface Modification", Applied Physics Letters, 83, 23, 4695-4697, (2003)
32. G. A. H. Wetzelaer, A. Najafi, R. J. P. Kist, M. Kuik and P. W. M. Blom, "
Efficient Electron Injection from Solution-Processed Cesium Stearate Interlayers in Organic Light-Emitting Diodes",Applied Physics Letters, 102, 5, 053301, (2013)
33. 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, 87, 1, 013504, (2005)
34. 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, 19, 15, 2010-2014, (2007)
35. H. Wu, F. Huang, Y. Mo, W. Yang, D. Wang, J. Peng and Y. Cao, "Efficient Electron Injection from A Bilayer Cathode Consisting of Aluminum and Alcohol-/ Water- Soluble Conjugated Polymers", Advanced Materials, 16, 20, 1826-1830, (2004)
36. F. Huang, H. Wu, D. Wang, W. Yang and Y. Cao, "Novel Electroluminescent Conjugated Polyelectrolytes Based on Polyfluorene", Chemistry of Materials, 16, 4, 708-716, (2004)
37. F. Huang, H. Wu and Y. Cao, "Water/Alcohol Soluble Conjugated Polymers as Highly Efficient Electron Transporting/Injection Layer in Optoelectronic Devices", Chemical Society Reviews, 39, 7, 2500-2521, (2010)
38. W. Ma, P. K. Iyer, X. Gong, B. Liu, D. Moses, G. C. Bazan and A. J. Heeger, "Water/Methanol-Soluble Conjugated Copolymer as An Electron-Transport Layer in Polymer Light-Emitting Diodes", Advanced Materials, 17, 3, 274-277, (2005)
39. R. Yang, H. Wu, Y. Cao and G. C. Bazan, "Control of Cationic Conjugated Polymer Performance in Light Emitting Diodes by Choice of Counterion", Journal of the American Chemical Society, 128, 45, 14422-14423, (2006)
40. R. Yang, A. Garcia, D. Korystov, A. Mikhailovsky, G. C. Bazan and T. Q. Nguyen, "Control of Interchain Contacts, Solid-State Fluorescence Quantum Yield, and Charge Transport of Cationic Conjugated Polyelectrolytes by Choice of Anion", Journal of the American Chemical Society, 128, 51, 16532-16536, (2006)
41. C. Hoven, R. Yang, A. Garcia, A. J. Heeger, T. Q. Nguyen and G. C. Bazan, "Ion Motion in Conjugated Polyelectrolyte Electron Transporting Layers", Journal of the American Chemical Society, 129, 36, 10976-10977, (2007)
42. C. V. Hoven, R. Yang, A. Garcia, V. Crockett, A. J. Heeger, G. C. Bazan and T. Q. Nguyen, "Electron Injection into Organic Semiconductor Devices from High Work Function Cathodes", Proceedings of the National Academy of Sciences of the United States of America, 105, 35, 12730-12735, (2008)
43. R. Yang, Y. Xu, X.-D. Dang, T.-Q. Nguyen, Y. Cao and G. C. Bazan, "Conjugated Oligoelectrolyte Electron Transport/Injection Layers for Organic Optoelectronic Devices", Journal of the American Chemical Society, 130, 11, 3282-3283, (2008)
44. F. Huang, X. Wang, D. Wang, W. Yang and Y. Cao, "Synthesis and Properties of A Novel Water-Soluble Anionic Polyfluorenes for Highly Sensitive Biosensors", Polymer, 46, 25, 12010-12015, (2005)
45. Y. Jin, G. C. Bazan, A. J. Heeger, J. Y. Kim and K. Lee, "Improved Electron Injection in Polymer Light-Emitting Diodes Using Anionic Conjugated Polyelectrolyte", Applied Physics Letters, 93, 12, 123304, (2008)
46. J. Fang, B. H. Wallikewitz, F. Gao, G. Tu, C. Müller, G. Pace, R. H. Friend, and Wilhelm T. S. Huck, "Conjugated Zwitterionic Polyelectrolyte as the Charge Injection Layer for High-Performance Polymer Light-Emitting Diodes", Journal of the American Chemical Society, 133, 4, 683-685, (2011)
47. C. Duan , L. Wang , K. Zhang , X. Guan , and F. Huang, "Conjugated Zwitterionic Polyelectrolytes and Their Neutral Precursor as Electron Injection Layer for High-Performance Polymer Light-Emitting Diodes", Advanced Materials, 23, 14, 1665-1669, (2011)
48. T. Yamamoto, H. Kajii and Y. Ohmori, "Improved Electron Injection from Silver Electrode for All Solution-Processed Polymer Light-Emitting Diodes with Cs2CO3: Conjugated Polyelectrolyte Blended Interfacial Layer", Organic Electronics, 15, 6, 1077-1082, (2014)
49. C. Min, C. Shi, W. Zhang, T. Jiu, J. Chen, D. Ma, and J. Fang, "A Small-Molecule Zwitterionic Electrolyte without a π-Delocalized Unit as a Charge-Injection Layer for High-Performance PLEDs", Angewandte Chemie-International Edition, 52, 12, 3417-3420, (2013)
50. B. Yin, H. Ma, S. Wang, and S. Chen, "Electrochemical Synthesis of Silver Nanoparticles Under Protection of Poly(N-Vinylpyrrolidone) ", Journal of Physical Chemistry B, 107, 34, 8898-8904, (2003)
51. Y. Xiong, I. Washio, J. Chen, H. Cai, Z. Y. Li and Y. Xia, "Poly(vinyl pyrrolidone): A Dual Functional Reductant and Stabilizer for the Facile Synthesis of Noble Metal Nanoplates in Aqueous Solutions", Langmuir, 22, 20, 8563-8570, (2006)
52. H. Wang, W. Zhang, C. Xu, X. Bi, B. Chen, and S. Yang, "Efficiency Enhancement of Polymer Solar Cells by Applying Poly(vinylpyrrolidone) as a Cathode Buffer Layer via Spin Coating or Self-Assembly", Acs Applied Materials & Interfaces, 5, 1, 26-34, (2013)
53. O. R. Miranda, N. R. Dollahon, and T. S. Ahmadi, "Critical Concentrations and Role of Ascorbic Acid (Vitamin C) in the Crystallization of Gold Nanorods within Hexadecyltrimethyl Ammonium Bromide (CTAB)/Tetraoctyl Ammonium Bromide (TOAB) Micelles", Crystal Growth & Design, 6, 12, 2747-2753, (2006)
54. J. A. Cornell, "Experiments with Mixtures : Designs, Models, and the Analysis of Mixture Data", 2nd ed., John Wiley & Sons, Inc., New York, (1990)
55. A. I. Khuri and J. A. Cornell, "Response Surfaces: Designs and Analyses", Chap. 9, 333-374, Marcel Dekker, Inc.,N. Y., (1987)
56. H. Scheffe, "Experiments with Mixtures", Journal of the Royal Statistical Society Series B-Statistical Methodology, B20, 2, 344-360, (1958)
57. N. R. Draper and H. Smith, "Applied Regression Analysis", 294-379, John Wiley & Sons, Inc., New York, (1981)
58. S. M. Lin and T. C. Wen, "A Mixture Design Approach to the Service Life and the Oxygen-Evolving Catalytic Activity of Ru-Sn-Ti Ternary Oxide Coated Electrodes", Journal of Applied Electrochemistry, 23, 5, 487-494, (1993)
59. S. M. Lin and T. C. Wen, "Oxygen Evolution on Ir-Ru-Sn Ternary Oxide-Coated Electrodes in H2SO4 Solution - An Approach Employing Statistical Experimental Strategy", Journal of the Electrochemical Society, 140, 8, 2265-2271, (1993)
60. Y. J. Li, C. C. Chang and T. C. Wen, "A Mixture Design Approach to Thermally Prepared Ir-Pt-Au Ternary Electrodes for Oxygen Reduction in Alkaline Solution", Journal of Applied Electrochemistry, 27, 2, 227-234, (1997)
61. C. H. Yang, Y. J. Li and T. C. Wen, "Mixture Design Approach to PEG-PPG- PTMG Ternary Polyol-Based Waterborne Polyurethanes", Industrial & Engineering Chemistry Research, 36, 5, 1614-1621, (1997)
62. C. H. Yang, H. J. Yang, T. C. Wen, M. S. Wu and J. S. Chang, "Mixture Design Approaches to IPDI-H6XDI-XDI Ternary Diisocyanate-Based Waterborne Polyurethanes, Polymer, 40, 4, 871-885, (1999)