近年來利用調控不同溶劑性質來引導聚(3-己基噻吩)(poly(3-hexylthiophene) , P3HT)在溶液中結晶受到廣大的關注，比起單純利用溶劑退火或是熱退火等後處理，此方法有利於大量製造結晶度較高的奈米纖維。由於良好的有機元件的性質通常取決於良好的結構，探究其溶劑性質對於結構的影響有其必要。
本文主要聚焦於聚P3HT在數種不同性質的稀薄溶液中的結構變化，利用三種對於主鏈支鏈親好性不同的良溶劑；THF親好主鏈的噻吩、而討厭支鏈的n-己基、環己烷的親好性與THF相反而甲苯介於兩者之間。再透過添加適量的醇類，組成雙成份混合溶劑可自由調控其聚集驅動力。經由激子耦合分析不同溶劑在一定熟化時間下的UV-vis光譜，我們發現貧溶劑的添加主要影響P3HT聚集速率的快慢，而對於P3HT在貧溶劑種類溶液中，最鄰近分子間庫倫耦合能J0變化不劇烈；J0主要受到混摻比例與良溶劑種類的影響而改變。
在THF系統中，溶液很快的形成較大尺度的團聚結構，但其奈米纖維呈散亂排列故不適合作為製程溶劑。在甲苯中形成單一而獨立的奈米纖維，除了與1-丙醇混摻的甲苯混合溶劑，其餘溶劑對對於奈米纖維的穩定定高，長時間熟化下仍不會形成大尺度的團聚結構。而環己烷系統在平衡下團聚物所占的比例比其他兩種溶劑高，且除了一維方向的π-π堆疊外，還會形成二維方向的排列片狀團聚。

Organic devices have attracted great interests due to their advantages of low cost, solution-based processes, and flexibility. Poly(3-hexylthiophene)(P3HT), as a typical linear conjugated polymer, have been applied in commercial processes.
In this study, we focused on the conformation of P3HT chains in three organic solvents of different selectivity. The chain conformation in the dilute solutions affected the morphology in solid state. By controlling the composition of binary co-solvent mixtures, the drive force of P3HT aggregation can be finely tuned.
THF is a good solvent for the thiophene backbone and but a poor one for the 3-hexyl side chain. In contrast, the affinity of cyclohexane shows an opposite trend, being good for 3-hexyl side chains but poor for the thiophene backbone. The selectivity of toluene lies between THF and cyclohexane. Next I added a series of alcohols with different CH2 length to tune the solvent quality to form P3HT aggregates with different nanostructures in solutions.
UV-vis and PL measurements were used to identify the correlations between solvent quality and the degree of ordering in aggregates. AFM and GIWAXD characterizations were carried out to investigate the P3HT morphology and the degree of crystallization in solid state. As the polarization of alcohols increased, the aging rate increased. the nearest-neighbor inter-chain coulombic coupling J0 did not significantly change. J0 is sensitive to the selectivity of solvents and the ratios of alcohols in binary co-solvent mixtures.
P3HT aged quickly in the solvent mixture of THF/alcohols and formed large-sized aggregation structures with disorder orientation. In the solvent mixtures of toluene/ alcohols (except for toluene/1-propanol), P3HT formed single fibers and well dispersed. In contrast, P3HT in the cosolvent mixtures of cyclohexane/alcohols was found to form bundles of nano-sized fibers with high orientational ordering.

1 Hoichang Yang, T.J.S., Lin Yang, Kilwon Cho, Chang Y. Ryu, Zhenan Bao.: ‘Effect of Mesoscale Crystalline Structure on the Field-Effect Mobility of Regioregular Poly(3-hexyl thiophene) in Thin-Film Transistors’, Advance Functional Materials 2005, 15, pp. 671-676
2 Ming He, L.Z., Jun Wang, Wei Han, Yuliang Yang, Feng Qiu, Zhiqun Lin: ‘Self-Assembly of All-Conjugated Poly(3-alkylthiophene) Diblock Copolymer Nanostructures from Mixed Selective Solvents’, ACSNANO, 2010, 4, pp. 3241-3247
3 Ye Huang, H.C., Charles C. Han: ‘Temperature Induced Structure Evolution of Regioregular Poly(3-hexylthiophene) in Dilute Solution and its Influence on Thin Film Morphology’, Macromolecules, 2010, 43, pp. 10031-10037
4 Yeong Don Park, H.S.L., Yeon Joo Choi, Donghoon Kwak, Jeong Ho Cho, Sichoon Lee, and Kilwon Cho: ‘Solubility-Induced Ordered Polythiophene Precursors for High-Performance Organic Thin-Film Transistors’, Advance Functional Materials, 2009, 19, pp. 1200-1206
5 Mincheol Chang, D.C., Boyi Fu, Elsa Reichmanis: ‘Solvent Based Hydrogen Bonding: Impact on Poly(3-hexylthiophene) Nanoscale Morphology and Charge Transport Characteristics’, ACSNANO, 2013, 7, pp. 5402-5413
6 Benjamin Schmidt-Hansberg, M.S., Nadia Grossiord, Yulia Galagan, Michael Baunach, Michael F.G. Klein, Alexander Colsmannd, Philip Scharfer, Uli Lemmer,, and Helmut Dosch, J.M., Esther Barrena, Wilhelm Schabel: ‘Investigation of non-halogenated solvent mixtures for high throughput fabrication of polymer - fullerenesolarcells’, Solar Energy Materials & Solar Cells, 2012, 96, pp. 195-201
7 Hansen, C.M.: ‘Hansen Solubility Parameters: A User's Handbook’ (2007, Second Edition edn. 2007)
8 Calynn E. Johnson, D.S.B.: ‘Poly(3-hexylthiophene) Aggregate Formation in Binary Solvent Mixtures: An Excitonic Coupling Analysis’, Journal of Polymer Science B: Polymer Physics, 2014, 52, pp. 526–538
9 Florian Machui, S.L., Xiangdong Zhu, Steven Abbott, Christoph J. Brabec: ‘Determination of the P3HT:PCBM solubility parameters via a binary solvent gradient method: Impact of solubility on the photovoltaic performance’, Solar Energy Materials & Solar Cells, 2012, 100, pp. 138-146
10 Claus Greve Madsen, A.S., Lene Jørgensen, Stefanía Baldursdottír, Natalie J. Medlicott: ‘Effect of Mixed Solvents on Polymer Conformation - Correlation between the Hildebrand/Hansen Solubility Parameters and the Intrinsic Viscosity of Polymer Solutions’, Annual Transactions of the Nordic Rheology Society, 2013, 21, pp. 347-352
11 Choong-Do Park, T.A.F., Jian Li, Bryan D. Vogt,: ‘High performance bulk-heterojunction organic solar cells fabricated with non-halogenated solvent processing’, Organic Electronics, 2011, 12, pp. 1465-1470
12 Duc T. Duong, B.W., Jason Lin, Chunki Kim, John Love, Balaji Purushothaman, John E. Anthony, Thuc-Quyen Nguyen: ‘Molecular Solubility and Hansen Solubility Parameters for the Analysis of Phase Separation in Bulk Heterojunctions’, Journal of Polymer Science B: Polymer Physics, 2012, 50, pp. 1405-1413
13 殷敬華, 莫.: ‘第一章 高分子的分子結構’: ‘現代高分子物理學’ (2001, 初版 edn.), pp. 1-24
14 Pei-Yin Chen, A.R., Hsin-Lung Chen, Show-An Chen: ‘Conformation and Fluorescence Property of Poly(3-hexylthiophene) Isolated Chains Studied by Single Molecule Spectroscopy: Effects of Solvent Quality and Regioregularity’, Macromolecules, 2013, 46, pp. 5657-5663
15 D. S. Wishart, B.D.S., F. M. Richards: ‘The Chemical Shift Index: A Fast and Simple Method for the Assignment of Protein Secondary Structure through NMR Spectroscopy’, Biochemistry, 1992, 31, pp. 1647-1651
16 Jung Ah Lim, F.L., Sunzida Ferdous, Murugappan Muthukumar, Alejandro L. Briseno: ‘Polymer semiconductor crystals’, Materialstoday, 2010, 13, pp. 14-24
17 Kaname Kanai, T.M., Hiroyuki Suzuki, Mina Inaba, Yukio Ouchib, Kazuhiko Seki: ‘Effect of annealing on the electronic structure of poly(3-hexylthiophene) thin film’, Physical Chemistry Chemical Physics, 2010, 12, pp. 273-282
18 Takuji Adachi, J.B., Robert J. Ono, Benjamin Hanson, Matthew C. Traub, Zong-Quan Wu, Zicheng Li. Joshua C. Bolinger, Venkat Ganesan, Christopher W. Bielawski, David A. Vanden Bout, Paul F. Barbara: ‘Regioregularity and Single Polythiophene Chain Conformation’, Journal of Physical Chemistry Letters, 2011, 2, pp. 1400-1404
19 Jin Young Oh, M.S., Tae Il Lee, Woo Soon Jang, Yuho Min, Jae-Min Myoung, Hong Koo Baik, Unyong Jeong: ‘Self-Seeded Growth of Poly(3-hexylthiophene) (P3HT) Nanofibrils by a Cycle of Cooling and Heating in Solutions’, Macromolecules, 2012, 45, pp. 7405-7413
20 Ye Huang, H.C., Charles C. Han: ‘Unimer Aggregate Equilibrium to Large Scale Association of Regioregular Poly(3-hexylthiophene) in THF Solution’, Macromolecules, 2011, 44, pp. 5020–5026
21 Wentao Xu, L.L., Haowei Tang, Hui Li, Xiaoli Zhao, Xiaoniu Yang: ‘Solvent-Induced Crystallization of Poly(3-dodecylthiophene):Morphology and Kinetics’, Journal of Physical Chemistry B, 2011, 115, pp. 6412-6420
22 Yuumi Takizawa, T.S., Toshiaki Miura: ‘Simulation Study of the Initial Crystallization Processes of Poly(3-hexylthiophene) in Solution: Ordering Dynamics of Main Chains and Side Chains’, Journal of Physical Chemistry B, 2013, 117, pp. 6282-6289
23 Mina Baghgar, J.A.L., Felicia Bokel, Ryan C. Hayward, Michael D. Barnes: ‘Effect of Polymer Chain Folding on the Transition from H- to J-Aggregate Behavior in P3HT Nanofiber’, Journal of Physical Chemistry C, 2014, 118, pp. 2229-2235
24 Jianhua Liu, M.A., Jianhua Zou, Saiful I. Khondaker, Lei Zhai: ‘Controlling Poly(3-hexylthiophene) Crystal Dimension: Nanowhiskers and Nanoribbons’, Macromolecules Communication, 2009, 42, pp. 9390-9393
25 Maarten J. M. Wirix, P.H.H.B., Heiner Friedrich, Nico A. J. M. Sommerdijk, Gijsbertus de With: ‘Three-Dimensional Structure of P3HT Assemblies in Organic Solvents Revealed by Cryo-TEM’, Nano Letters, 2014, 14, pp. 2033-2038
26 Jong K. Keum, K.X., Ilia N. Ivanov, Kunlun Hong, James F. Browning, Gregory S. Smith, Ming Shao, Kenneth C. Littrell, Adam J. Rondinone, E. Andrew Payzant, Jihua Chenb, Dale K. Hensley ‘Solvent quality-induced nucleation and growth of parallelepiped nanorods in dilute poly(3-hexylthiophene) (P3HT) solution and the impact on the crystalline morphology of solution-cast thin film’, CrystEngComm, 2013, 15, pp. 1114-1124
27 Amy B. Koren, M.D.C., Anthony H. Francis, Jeff W. Kampf: ‘Intermolecular Interactions in π-Stacked Conjugated Molecules. Synthesis, Structure, and Spectral Characterization of Alkyl Bithiazole Oligomers’, Journal of the American Chemical Society, 2003, 125, pp. 5040-5050
28 W. Ten Hoeve, H.W., E. E. Havinga, E. W. Meijer: ‘Substituted 2,2':5',2'':5'',2''':5''',2'''':5'''',2''''': 5''''',2'''''':5'''''',2''''''':5''''''',2'''''''':5'''''''',2''''''''':5''''''''',2''''''''''-undecithiophenes, the longest characterized oligothiophenes’, Journal of the American Chemical Society, 1991, 113, pp. 5887-5889
29 Tsuyoshi Izumi, S.K., Kazuo Takimiya, Yoshio Aso, Tetsuo Otsubo: ‘Synthesis and Spectroscopic Properties of a Series of β-Blocked Long Oligothiophenes up to the 96-mer:   Revaluation of Effective Conjugation Length’, Journal of the American Chemical Society, 2003, 125, pp. 5286-5287
30 Frank C. Spano, C.S.: ‘H- and J-Aggregate Behavior in Polymeric Semiconductors’, Annual Review of Physical Chemistry, 2014, 65, pp. 477-500
31 Nicholas J. Turro, J.C.S., V. Ramamurthy: ‘Principles of Molecular Photochemistry: An Introduction’ (2008, 1st edn. 2008)
32 http://en.wikipedia.org/wiki/Franck%E2%80%93Condon_principle, 20140728.
33 Spano, F.C.: ‘Modeling disorder in polymer aggregates: The optical spectroscopy of regioregular poly(3-hexylthiophene) thin films’, Journal of Chemical Physics, 2005, 122, pp. 234701
34 Spano, F.C.: ‘The Spectral Signatures of Frenkel Polarons in H- and J-Aggregates’, Accounts of Chemical Reseach, 2010, 43, pp. 429-439
35 Christina Scharsich, R.H.L., Michael Sommer, Udom Asawapirom, Ullrich Scherf, Mukundan Thelakkat, Dieter Neher, Anna Ko¨hler: ‘Control of Aggregate Formation in Poly(3-hexylthiophene) by Solvent, Molecular Weight, and Synthetic Method’, Journal of Polymer Science B: Polymer Physics, 2012, 50, pp. 442-453
36 Yi-Kang Lan, C.-I.H.: ‘A Theoretical Study of the Charge Transfer Behavior of the Highly Regioregular Poly-3-hexylthiophene in the Ordered State’, Journal of Physical Chemistry B, 2008, 112, pp. 14857-14862
37 Yi-Kang Lan, C.-I.H.: ‘Charge Mobility and Transport Behavior in the Ordered and Disordered States of the Regioregular Poly(3-hexylthiophene)’, Journal of Physical Chemistry B, 2009, 113, pp. 14555-14564
38 H. Sirringhaus, P.J.B., 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, D. M. de Leeuw: ‘Two-dimensional charge transport in self-organized, high-mobility conjugated polymers’, Letters to Nature, 1999, 401, pp. 685-688
39 Wentao Xu, H.T., Hongying Lv, Jun Li, Xiaoli Zhao, Hui Li, Ning Wanga, Xiaoniu Yang: ‘Sol-gel transition of poly(3-hexylthiophene) revealed by capillary measurements: phase behaviors, gelation kinetics and the formation mechanism’, Soft Matter, 2012, 8, pp. 726-733
40 汪建民: ‘第六章 掃描式電子顯微鏡分析’: ‘材料分析 Materials Analysis’ (1998, 初版 edn.), pp. 121-148
41 林智仁: ‘場發射式掃瞄式電子顯微鏡簡介’, in Editor (Ed.)^(Eds.): ‘Book 場發射式掃瞄式電子顯微鏡簡介’ (2002, edn.), pp. 94-99
42 Han Yan, Y.Y., Zai Yu, Zhixiang Wei: ‘Self-Assembling Branched and Hyperbranched Nanostructures of Poly(3-hexylthiophene) by a Solution Process’, Journal of Physical Chemistry C, 2011, 115, pp. 3257-3262
43 Jui-Fen Chang, B.S., Dag W. Breiby, Martin M. Nielsen, Theis I. Solling, Mark Giles, Iain McCulloch, Henning Sirringhaus: ‘Enhanced Mobility of Poly(3-hexylthiophene) Transistors by Spin-Coating from High-Boiling-Point Solvents’, Chemistry of Materials, 2004, 16, pp. 4772-4776
44 Edwards T. Niles, J.D.R., Hajime Yamagata, Adam J. Wise, Frank C. Spano, Adam J. Moulé, John K. Grey: ‘J-Aggregate Behavior in Poly-3-hexylthiophene Nanofibers’, Journal of Physical Chemistry Letters, 2012, 3, pp. 259-263
45 汪建民: ‘第十一章 掃描式探針顯微鏡分析’: ‘材料分析 Materials Analysis’ (1998, 初版 edn.), pp. 259-299
46 http://sld-calculator.appspot.com/, 20140730.
47 Yuanyuan Han, Y.G., Yingfei Chang, Yanhou Geng, Zhaohui Su.: ‘Chain Folding in Poly(3-hexylthiophene) Crystals’, Macromolecules, 2014, 47, pp. 3708-3712
48 Glenn W. Heffner, D.S.P.: ‘Molecular Characterization of Poly(3-hexylthiophene)’, Macromolecules, 1991, 24, pp. 6295-6399