共軛高分子太陽電池因具有質輕、製程簡易、可製作大面積等特色，向來為研究低成本太陽電池的一個重要領域。在元件結構上，一般是使用塊材異質接面(bulk heterojunction)結構，利用其具大面積激子分離區域的優點，使元件有較佳的表現效率。近年來，染料感光太陽電池及小分子太陽電池，均分別發展出更理想的排列式塊材異質接面結構(ordered bulk heterojunction)，使載子的傳輸效率提高，大幅增加元件的轉換效率。
本研究以P3HT (poly(3-hexylthiophene))共軛高分子為電洞傳輸材料，5nm×10nm硒化鎘(CdSe)無機膠體奈米管為電子傳輸材料，摻雜混合(blend)而為主動層材料，以旋轉塗佈(spin-coating)的方式在元件上形成單層塊材異質接面結構，在532nm單頻光下的能量轉換效率可達1%。而為了使元件達到較好的載子傳輸效率，以單層塊材異質接面結構為基礎，使用旋轉塗佈法形成多層結構，來模擬排列式塊材異質接面結構。在實驗中，利用奈米晶體受熱固結(sintering)的特性，可控制讓元件中層與層之間僅些微互溶，達成理想的多層異質接面結構。
在研究中，成功製作出blend/CdSe及blend(P3HT-rich)/blend排列式塊材異質接面結構，其元件串聯電阻較單層塊材異質接面結構減小了數倍，使元件的光電流及填充因子均大幅的提升。在能量轉換效率上，blend/CdSe雙層結構在單頻光的照射下高達2.4%，blend(P3HT-rich)/blend雙層結構更高達3.1%！

Polymer solar cells exhibit many advantages such as the lightweight、processing feasibility and the potential to scale up to large area. Therefore polymer solar cells have been under intensive research. It usually contains single layer bulk heterojunction structure in the device. With large area for exciton separating, the efficiency of the device can be greatly improved. Recently, a better structure called ordered bulk heterojunction has been developed in dye-sensitized solar cells and molecular solar cells. It helps carriers transport and increases the efficiency of the device dramatically.
In our study, we use P3HT conjugated polymer as hole transport material and 5nm×10nm CdSe inorganic colloidal nanorods as electron transport material. Blending two of them as the active layer, we form a bulk heterojunction film on the device with spin-coating. Under the illumination of monochromatic light with 532nm wavelength, the power conversion efficiency reaches 1%. In order to increase the carrier transport efficiency, we use single layer bulk heterojunction as basic structure and develop multilayer structure with spin-coating to achieve the similar effect of ordered bulk heterojunction. Using the sintering property of nanocrystals when annealed, we can create multilayer bulk heterojunction structure by slightly mixing the layers at the interface.
In this study, we successfully developed blend/CdSe and blend(P3HT-rich)/blend ordered bulk heterojunction structures. Comparing to single layer bulk heterojunction, the series resistance decreases several times in ordered bulk heterojunction structure. It makes short circuit current and fill factor increase largely. The power conversion efficiency in blend/CdSe structure is 2.4% under the illumination of monochromatic light with 532nm wavelength. In blend(P3HT-rich)/blend structure, the efficiency even reaches 3.1%！

摘要 i
致謝 iv
目錄 v
第一章 序論 1
1.1 研究背景 1
1.1.1 太陽電池產業發展, 1
1.1.2 有機太陽電池學術發展概況 3
1.2 研究動機 5
1.2.1 無機太陽電池的瓶頸 5
1.2.2 有機太陽電池的機會與困難 5
1.2.3 新的概念與新的機會 --- ordered bulk heterojunction 7
1.3論文架構 10
第二章 實驗理論 11
2.1 太陽電池基本原理 11
2.1.1太陽電池等效電路 11
2.1.2 太陽電池基本參數 14
2.2 共軛高分子材料特性及研究應用 15
2.2.1 共軛高分子的光電特性 15
2.2.2 共軛高分子的發展與應用 17
2.3 膠狀奈米晶體特性及合成製備 17
2.3.1 膠狀奈米晶體特性 17
2.3.2 膠狀奈米晶體合成製備 18
2.4 有機太陽電池元件理論 19
2.4.1 共軛高分子元件能帶圖 19
2.4.2 共軛高分子的載子傳輸理論 22
2.4.3 有機太陽電池能量轉換效率分析 24
第三章 實驗方法 31
3.1 元件結構 31
3.2 元件材料選擇與能帶圖 31
3.2.1 donor材料 --- P3HT 31
3.2.2 acceptor材料 --- CdSe奈米晶體 33
3.2.4元件能帶圖 35
3.3 元件製作與量測 36
3.3.1 ITO圖樣化與清洗 36
3.3.2主動層成膜製備及電極蒸鍍 38
3.3.3封裝與量測 40
第四章 實驗結果與分析 41
4.1單層、雙層及bulk heterojunction結構比較 41
4.2單層bulk heterojunction結構 44
4.2.1 blend單層結構摻雜不同CdSe濃度比較 44
4.2.2 blend單層結構膜厚及照光分析 45
4.3 雙層ordered bulk heterojunction結構 48
4.3.1 blend/CdSe雙層結構 48
4.3.2 blend(P3HT-rich) /blend雙層結構 53
第五章 總結 57
參考文獻 58

1. A. Goetzberger, C. Hebling, and H.-W. Schock, “Photovoltaic materials, history, status and outlook,” Mater. Sci. and Engr. R 40, 1 (2003).
2. H. Spanggaard and F. C. Krebs, “A brief history of the development of organic and polymeric photovoltaics,” Sol. Energy Mater. Sol. Cells 83, 125 (2004).
3. D. M. Chapin, C. S. Fuller, and G.L. Pearson, “A New Silicon pn Junction Photocell for Converting Solar Radiation into Electrical Power,” J. Appl. Phys. 25, 676 (1954).
4. J. Zhao, A. Wang, and M. A. Green, “24.5% efficiency silicon PERT cells on MCZ substrates and 24.7% efficiency PERL cells on FZ substrates,” Prog. Photovolt. : Res. Appl. 7, 471 (1999).
5. D. E. Carlson and C. R. Wronski, “Amorphous silicon solar cell,” Appl. Phys. Lett. 28, 671 (1976).
6. K. Sriprapa and P. Sichanugrist, "High efficiency amorphous/microcrystalline silicon solar cell fabricated on metal substrate," Photovoltaic Energy Conversion, 2003. Proceedings of 3rd World Conference on Volume 3, Page(s):2799 - 2800 (2003).
7. M. A. Contreras, B. Egaas, K. Ramanathan, J. Hiltner, A. Swartzlander, F. Hason, and R. Noufi, “Properties of 19.2% efficiency ZnO/CdS/CuInGaSe2 thin-film solar cells,” Prog. Photovolt.: Res. Appl. 7, 311 (1999).
8. P. Maycock, “China PV Booming,” Photovoltaic News, May (2004).
9. C. J. Brabec, S. E. Shaheen, C. Winder, and N. S. Sariciftci, “Effect of LiF/metal electrodes on the performance of plastic solar cells,” Appl. Phys. Lett. 80, 1288 (2002).
10. G. Li, V. Shrotriya, J. Huang, Y. Yao, and Y. Yang, “High-efficiency solution processable polymer photovoltaic cells by self-organization of polymer blends,” Nature Mater. 4, 864, (2005).
11. M. A. Green, K, Emery, D. L. Ling, S. Igari, and W. Warta, “Solar Cell Efficiency Tables (Version 24),” Prog. Photovolt. : Res. Appl. 12, 365 (2004).
12. R. McConnell, S. Kurtz, and M. Symko-Davies, “Concentrator Photovoltaic Technologies,” Refocus. July/August (2005).
13. C. W. Tang, “Two-layer organic photovoltaic cell,” Appl. Phys. Lett. 48, 183 (1986).
14. G. Yu, K. Pakbaz, and A. J. Heeger, “Semiconducting polymer diodes: Large size, low cost photodetectors with excellent visible-ultraviolet sensitivity,” Appl. Phys. Lett. 64, 3422 (1994).
15. J. Nelson, “Organic photovoltaic films,” Curr. Opin. Solid State Mater. Sci. 6, 87 (2002).
16. B. O’Regan and M. A. Gr□tzel, “A low cost, high efficiency solar cell based on dye-sensitized colloidal TiO2 films,” Nature 353, 737 (1991).
17. L. Bin, W. Liduo, K. Bonan, W. Peng, and Q. Yong, “Review of recent progress in solid-state dye-sensitized solar cells,” Sol. Energy Mater. Sol. Cells 90, 549 (2006).
18. website of “Research Institute of Innovative Technology for the Earth, RITE” (http://www.rite.or.jp/)
19. website of “Energy Information Administration, EIA” (http://www.eia.doe.gov/)
20. B. Sun, H. J. Snaith, A. S. Dhoot, S.Westenhoff, and N. C. Greenham, “Vertically segregated hybrid blends for photovoltaic devices with improved efficiency,” J. Appl. Phys. 97, 014914 (2005).
21. K. M. Coakley and M. D. McGehee, “Conjugated polymer photovoltaic cells,” Chem. Mater. 16, 4533 (2004).
22. M. Law, L. E. Greene, J. C. Johnson, R. Saykally, and P. Yang, “Nanowire dye-sensitized solar cells,” Nature Mater. 4, 455 (2005).
23. M. Baldo, M. Deutsch, P. Burrows, H. Gossenberger, M. Gerstenberg, V. Ban, and S. Forrest, “Organic vapor phase deposition,” Adv. Mater. 10, 1505 (1998).
24. F. Yang, M. Shtein, and S.R. Forrest, “Controlled growth of a molecular bulk heterojunction photovoltaic cell“, Nature Mater. 4, 37 (2005).
25. N. C. Greenham, X. G. Peng, and A. P. Alivisatos, “Charge separation and transport in conjugated-polymer/semiconductor-nanocrystal composites studied by photoluminescence quenching and photoconductivity,” Phys. Rev. B 54, 17628 (1996).
26. W. U. Huynh, J. J. Dittmer, G. Whiting, W. Libby, and A. P. Alivisatos, “Controlling the Morphology of Nanocrystal-polymer Composites for Solar Cells,” Adv. Funct. Mater. 13, 73 (2003).
27. W. U. Huynh, J. J. Dittmer, N. Teclemariam, D. Milliron, and A. P. Alivisatos, K. W. J. Barnham, “Charge Transport in Hybrid Nanorod-Polymer Composite Photovoltaic. Cells,” Phys. Rev. B 67, 115326 (2003).
28. L. B. Smilowitz, “Conjugated polymers: modern electronic materials,” Circuits and Devices Magazine, IEEE, 10, 19 (1994).
29. T. Ahn, S. Y. Song, and H. K. Shim, “Highly Photoluminescent and Blue-Green Electroluminescent Polymers: New Silyl- and Alkoxy-Substituted Poly(p-phenylenevinylene) Related Copolymers Containing Carbazole or Fluorene Groups,” Macromolecules, 33, 6764 (2000).
30. H. Shirakawa, E. J. Louis, A. G. MacDiarmid, C. K. Chiang, and A. J. Heeger, “Synthesis of Electrically Conducting Organic Polymers: Halogen Derivatives of Polyacetylene, (CH)x,” J. Chem. Soc., Chem. Commun. 578 (1977).
31. Y. Yin and A. P. Alivisatos, “Colloidal Nanocrystal Synthesis and the Organic-Inorganic Interface,” Nature 437, 664 (2005).
32. A. P. Alivisatos, “Perspectives on the physical chemistry of semiconductor nanocrystals,” J. Phys. Chem. 100, 13226 (1996).
33. C. B. Murray, D. J. Norris, and M. G. Bawendi, “Synthesis and Characterization of Nearly Monodisperse CdE(E = S, Se, Te) Semiconductor Nanocrystallites,” J. Am. Chem. Soc. 115, 8706 (1993).
34. X. Michalet, F. F. Pinaud, L. A. Bentolila, J. M. Tsay, S. Doose, J. J. Li, G. Sundaresan, A. M. Wu, S. S. Gambhir, and S. Weiss, “Quantum dots for live cells, in vivo imaging, and diagnostics,” Science 307, 538 (2005).
35. N. Tessler, V. Medvedev, M. Kazes, S. Kan, and U. Banin, “Efficient near-infrared polymer nanocrystal light-emitting diodes,” Science 295, 1506 (2002).
36. M. Kazes, D. Y. Lewis, Y. Ebenstein, T. Mokari, and U. Banin, “Lasing from semiconductor quantum rods in a cylindrical microcavity,” Adv. Mater. 14, 317 (2002).
37. W. U. Huynh, J. J. Dittmer, and A. P. Alivisatos, “Hybrid Nanorod-Polymer Solar Cells,” Science 295, 2425 (2002)
38. website of A. P. Alivisatos Group (http://www.cchem.berkeley.edu/~pagrp/)
39. X. Peng, L. Manna, W. Yang, J. Wickham, E. Scher, A. Kadavanich, and A.P. Alivisatos, “Shape control of CdSe nanocrystals,” Nature 404, 59 (2000).
40. Liberato Manna, Erik C. Scher, and A. Paul Alivisatos “Synthesis of Soluble and Processable Rod-,Arrow-, Teardrop-, and Tetrapod-Shaped CdSe Nanocrystals,” J. Am. Chem. Soc. 122, 12700 (2000).
41. X. Peng, “Mechanisms for the Shape-Control and Shape-Evolution of Colloidal Semiconductor Nanocrystals,” Adv. Mater. 15, 459 (2003).
42. I. G. Hill, A. Rajagopal, A. Kahn, and Y. Hu, “Molecular level alignment at organic semiconductor-metal interfaces,” Appl. Phys. Lett. 73, 662 (1998).
43. H. Ishii, K. Sugiyama, E. Ito, and K. Seki, “Energy Level Alignment and Interfacial Electronic Structures at Organic/Metal and Organic/Organic Interfaces,” Adv. Mater. 11, 605 (1999).
44. I. G. Hill, A. J. Makinen, and Z. H. Kafafi, “Initial stages of metal/organic semiconductor interface formation,” J. Appl. Phys. 88, 889 (2000).
45. S. Karg, M. Meier, and W. Riess, “Light-emitting diodes based on poly-p-phenylene-vinylene: I. Charge-carrier injection and transport,” J. Appl. Phys. 82, 1951 (1997).
46. R. H. Fowler and L. Nordheim, Proc. R. Soc. London Ser. A 119, 173 (1928).
47. N. F. Mott and D. Gurney. Electronic Processes in Ionic Crystals. Oxford, New York, 1940.
48. J. Frenkel, “On pre-breakdown phenomena in insulators and electric semiconductors,” Phys. Rev. 54, 647 (1938).
49. D. M. Pai, “Transient photoconductivity in poly(N-vinylcarbazole),” J. Chem. Phys. 52, 2285 (1970).
50. P. W. M. Blom, M. J. M. de Jong, and M. G. van Munster, “Electric-field and temperature dependence of the hole mobility in poly(p-phenylene vinylene),” Phys. Rev. B 55, 656 (1997).
51. D. Moses, J. Wang, A. J. Heeger, N. Kirova, and S. Brazovski, “Singlet exciton binding energy in poly(phenylene vinylene),” PNAS 58, 13496 (2001).
52. A. Ruini, M. J. Caldas, G. Bussi, and E. Molinari, “Solid State Effects on Exciton States and Optical Properties of PPV,” Phys. Rev. Lett. 88, 206403 (2002).
53. website of “University of Texas at Austin, Center for Space Research”
(http://www.csr.utexas.edu)
54. J. M. Halls, K. Pichler, R. H. Friend, S. C. Moratti, and A. B. Holmes, “Exciton diffusion and dissociation in a poly(p-phenylenevinylene)/C60 heterojunction photovoltaic cell,” Appl. Phys. Lett 68, 3120 (1996).
55. M. Theander, A. Yartsev, D. Zigmantas, V. Sundstr□m, W. Mammo, M. R. Anderson, and O. Ingan□s, “Photoluminescence quenching at a polythiophene/C60 heterojunction,” Phys. Rev. B 61, 12957 (2000).
56. T. J. Savenije, J. M. Warman, and A.Goossens, “Visible light sensitisation of titanium dioxide using a phenylene vinylene polymer,” Chem. Phys. Lett. 287, 148 (1998).
57. A. Haugeneder, M. Neges, C. Kallinger, W. Spirkl, U. Lemmer, J. Feldman, U. Scherf, E. Harth, A. G□gel, and K. M□llen, “Exciton diffusion and dissociation in conjugated polymer/fullerene blends and heterostructures,” Phys. Rev. B, 59, 15346 (1999).
58. C. J. Brabec, A. Cravino, T. Fromherz, N. S. Sariciftci, M. Minse, L. Sanchez, and J.C. Hummelen, “Origin of the Open Circuit Voltage of Plastic Solar Cells,” Adv. Funct. Mater. 11, 374 (2001).
59. C. J. Brabec, “Organic photovoltaics : technology and market,” Sol. Energy Mater. Sol. Cells, 83, 273 (2004).
60. H. J. Snaith, N. C. Greenham, and R. H. Friend, “The Origin of Collected Charge and Open-Circuit Voltage in Blended Polyfluorene Photovoltaic Devices,” Adv. Mater. 16, 1640 (2004).
61. 太陽能工程–太陽電池篇 莊嘉琛 金華科技圖書股份有限公司 民86.
62. H. Sirringhaus, P. J. Brown, R. H. Friend, M. M. Nielsen, K. Bechgaard, B. M. W. Langeveld-Voss, A. J. H. Spiering, R. A. J. Janssen, E. W. Meijer, P. Herwig, and D. M. de Leeuw, “Two-dimensional charge transport in self-organized, high-mobility conjugated polymers,” Nature, 401, 685 (1999).
63. J. E. Bowen Katari, V. L. Colvin, and A. P. Alivisatos, “X-ray Photoelectron Spectroscopy of CdSe Nanocrystals with Applications to Studies of the Nanocrystal Surface,” J. Phys. Chem. 98, 4109 (1994).
64. M. Kuno, J. K. Lee, B. O. Dabbousi, F. V. Mikulec, and M. G. Bawendi, “The band edge luminescence of surface modified CdSe nanocrystallites:Probing the luminescing state”, J. Chem. Phys. 106, 9869 (1997).
65. B. S. Kim, L. Avila, L. E. Brus, and I. P. Herman, “Organic ligand and solvent kinetics during the assembly of CdSe nanocrystal arrays using infrared attenuated total reflection,” Appl. Phys. Lett. 76, 3715 (2000).
66. C. Zhang, S. O’Brien, and L. Balogh, “Comparison and Stability of CdSe Nanocrystals Covered with Amphiphilic Poly(Amidoamine) Dendrimers,” J. Phys. Chem. B 106, 10316 (2002).
67. B. Sun, E. Marx, and N. C. Greenham, “Photovoltaic Devices Using Blends of Branched CdSe Nanoparticles and Conjugated Polymers,” Nano Lett. 3, 961 (2003).