Poly(3-alkylthiophenes) (P3ATs)因為其可溶液製程、可靈活調整的化學結構以及其優秀的電洞傳輸性能而被廣泛地運用於各種有機電子元件，在這些聚噻吩衍生物中又以poly(3-hexylthiophene) (P3HT)最具有代表性且被深入地研究，許多研究都指出立體規則度(regioregularity , R.R.)與分子量對於高分子堆疊及排列有很大的影響力，而這對於載子傳輸是很重要的。但是相對的較少有人研究R.R.及分子量對於其它具有側鏈官能基的P3ATs的影響，而完整且系統性的研究是需要的。
此外，將一硫元素加入烷基側鏈基已經被證明可以有效的對高R.R.的P3HT及其衍生物的固態結構進行微調。這裡我們合成並分析了poly(3-alkylthio-thiophene) (P3ATTs)這一系列的高分子半導體包括poly(3-hexylthiothiophene) (P3HTT) (P3HTT)、poly(3-decylthiothiophene) (P3DTT)與poly(3-(2-ethyl)hexylthiothiophene) (P3EHTT)，並且探討了R.R.與分子量對於P3HTT的影響。透過將硫烷基測鏈取代烷基測鏈，π-π堆疊的距離從原本P3HT的3.88 Å縮近至P3HTT 的3.76 Å，而π-π堆疊的距離與主鏈的排列的方向性是決定元件效能的兩個最關鍵性的因素，因此溶液剪切力塗佈法被選擇用來製備高方向性高分子薄膜並應用於有機場效應電晶體，於P3HTT與P3DTT的電洞遷移率分別達到1.48×10-2 cm2 V-1 s-1與7.67×10-3 cm2 V-1 s-1。

Poly(3-alkylthiophenes) (P3ATs) have been used broadly in organic electronic application by virtue of its solution processability, tunable chemical structure and high hole mobility. Among these polythiophene derivatives, poly(3-hexylthiophene) (P3HT) is most representative and well-studied, and many studies revealed polymer regioregularity (R.R.) and molecular weight have an influence on molecular packing and ordering of polymers, which is important to charge transfer. However, there is less research about the effects of regioregularity or molecular weight on other P3ATs with functionalized sidechain, and the systematic research is needed.
Furthermore, alkyl sidechain substituent with a sulfur atom has been proven to enable fine tuning of the solid-state organization of the corresponding regioregular P3HT analogues. In this paper, we present the synthesis and characterization of a series of poly(3-alkylthiothiophene) (P3ATT)-based polymer semiconductors including poly(3-hexylthiothiophene) (P3HTT)、poly(3-decyl-thiothiophene) (P3DTT) and poly(3-(2-ethyl)hexylthiothiophene) (P3EHTT). P3HTT with various R.R. and molecular weights were also discussed. In this case, the π-π stacking distance successfully decreased from 3.88 Å to 3.76 Å by substituting hexyl sidechain by thiohexyl sidechain. Since both π-π interaction and backbone alignment are significant factors affecting charge transport behavior, unidirectional solution shearing method was applied to fabricate oriented polymer thin film for organic field effect transistor, reaching the mobility to 1.48×10-2 cm2 V-1 s-1 and 7.67×10-3 cm2 V-1 s-1 for P3HTT and P3DTT, respectively.

1. Paterson, A. F.; Singh, S.; Fallon, K. J.; Hodsden, T.; Han, Y.; Schroeder, B. C.; Bronstein, H.; Heeney, M.; McCulloch, I.; Anthopoulos, T. D., Recent Progress in High‐mobility Organic Transistors: A Reality Check. Adv. Mater. 2018, 30 (36), 1801079.
2. Shirakawa, H.; Louis, E. J.; MacDiarmid, A. G.; Chiang, C. K.; Heeger, A. J., Synthesis of Electrically Conducting Organic Polymers: Halogen Derivatives of Polyacetylene,(CH) x. J. Chem. Soc., Chem. Commun. 1977, (16), 578-580.
3. Guo, X.; Facchetti, A.; Marks, T. J., Imide and Amide-Functionalized Polymer Semiconductors. Chem. Rev. 2014, 114 (18), 8943-9021.
4. Zaumseil, J.; Sirringhaus, H., Electron and Ambipolar Transport in Organic Field-Effect Transistors. Chem. Rev. 2007, 107 (4), 1296-1323.
5. Diao, Y.; Shaw, L.; Bao, Z.; Mannsfeld, S. C., Morphology Control Strategies for Solution-Processed Organic Semiconductor Thin Films. Energy Environ. Sci. 2014, 7 (7), 2145-2159.
6. Lee, W. H.; Kim, D. H.; Jang, Y.; Cho, J. H.; Hwang, M.; Park, Y. D.; Kim, Y. H.; Han, J. I.; Cho, K., Solution-Processable Pentacene Microcrystal Arrays for High Performance Organic Field-Effect Transistors. Appl. phys. lett. 2007, 90 (13), 132106.
7. Li, H.; Tee, B. C.; Cha, J. J.; Cui, Y.; Chung, J. W.; Lee, S. Y.; Bao, Z., High-Mobility Field-Effect Transistors from Large-Area Solution-Grown Aligned C60 Single Crystals. J. Am. Chem. Soc. 2012, 134 (5), 2760-2765.
8. Chen, J.; Shao, M.; Xiao, K.; He, Z.; Li, D.; Lokitz, B. S.; Hensley, D. K.; Kilbey, S. M.; Anthony, J. E.; Keum, J. K., Conjugated Polymer-Mediated Polymorphism of A High Performance, Small-Molecule Organic Semiconductor with Tuned Intermolecular Interactions, Enhanced Long-Range Order, and Charge Transport. Chem. Mater. 2013, 25 (21), 4378-4386.
9. Shin, N.; Kang, J.; Richter, L. J.; Prabhu, V. M.; Kline, R. J.; Fischer, D. A.; DeLongchamp, D. M.; Toney, M. F.; Satija, S. K.; Gundlach, D. J., Vertically Segregated Structure and Properties of Small Molecule–Polymer Blend Semiconductors for Organic Thin‐Film Transistors. Adv. Funct. Mater. 2013, 23 (3), 366-376.
10. Yuan, Y.; Giri, G.; Ayzner, A. L.; Zoombelt, A. P.; Mannsfeld, S. C.; Chen, J.; Nordlund, D.; Toney, M. F.; Huang, J.; Bao, Z. J. N. c., Ultra-High Mobility Transparent Organic Thin Film Transistors Grown by an Off-Centre Spin-Coating Method. Nat. Commun. 2014, 5 (1), 1-9.
11. Qi, Z.; Zhang, F.; Di, C.-a.; Wang, J.; Zhu, D., All-Brush-Painted Top-Gate Organic Thin-Film Transistors. J. Mater. Chem. C 2013, 1 (18), 3072-3077.
12. Lin, X.; Klenk, R.; Wang, L.; Köhler, T.; Albert, J.; Fiechter, S.; Ennaoui, A.; Lux-Steiner, M. C., 11.3% Efficiency Cu (In, Ga)(S, Se) 2 Thin Film Solar Cells via Drop-on-Demand Inkjet Printing. Energy Environ. Sci. 2016, 9 (6), 2037-2043.
13. Chen, Y.; Li, X.; Xiao, Y.; Wang, S., Solution Processed Large-Scale Small Molecular Organic Field-Effect Transistors. Prog. Chem. 2017, 29 (4), 359-372.
14. Xu, J.; Wu, H.-C.; Zhu, C.; Ehrlich, A.; Shaw, L.; Nikolka, M.; Wang, S.; Molina-Lopez, F.; Gu, X.; Luo, S.; Zhou, D.; Kim, Y.-H.; Wang, G.-J. N.; Gu, K.; Feig, V. R.; Chen, S.; Kim, Y.; Katsumata, T.; Zheng, Y.-Q.; Yan, H.; Chung, J. W.; Lopez, J.; Murmann, B.; Bao, Z., Multi-Scale Ordering in Highly Stretchable Polymer Semiconducting Films. Nat. Mater. 2019, 18 (6), 594-601.
15. Tsumura, A.; Koezuka, H.; Ando, T., Macromolecular Electronic Device: Field‐Effect Transistor with a Polythiophene Thin Film. Appl. Phys. Lett. 1986, 49 (18), 1210-1212.
16. Zhou, E.; He, C.; Tan, Z. A.; Yang, C.; Li, Y., Effect of Side‐Chain End Groups on the Optical, Electrochemical, and Photovoltaic Properties of Side‐Chain Conjugated Polythiophenes. J Polym. Sci. Pol. Chem. 2006, 44 (16), 4916-4922.
17. Kline, R. J.; DeLongchamp, D. M.; Fischer, D. A.; Lin, E. K.; Richter, L. J.; Chabinyc, M. L.; Toney, M. F.; Heeney, M.; McCulloch, I., Critical Role of Side-Chain Attachment Density on the Order and Device Performance of Polythiophenes. Macromolecules 2007, 40 (22), 7960-7965.
18. Ho, V.; Boudouris, B. W.; Segalman, R. A., Tuning Polythiophene Crystallization Through Systematic Side Chain Functionalization. Macromolecules 2010, 43 (19), 7895-7899.
19. Ong, B. S.; Wu, Y.; Liu, P.; Gardner, S., Structurally Ordered Polythiophene Nanoparticles for High‐Performance Organic Thin‐Film Transistors. Adv. Mater. 2005, 17 (9), 1141-1144.
20. Hamadani, B.; Gundlach, D.; McCulloch, I.; Heeney, M., Undoped Polythiophene Field-Effect Transistors with Mobility of 1 cm 2 V− 1 s− 1. Appl. Phys. Lett. 2007, 91 (24), 243512.
21. Heeney, M.; Bailey, C.; Genevicius, K.; Shkunov, M.; Sparrowe, D.; Tierney, S.; McCulloch, I., Stable Polythiophene Semiconductors Incorporating Thieno [2, 3-b] Thiophene. J. Am. Chem. Soc. 2005, 127 (4), 1078-1079.
22. Li, Y.; Wu, Y.; Liu, P.; Birau, M.; Pan, H.; Ong, B. S., Poly (2, 5‐bis (2‐thienyl)‐3, 6‐dialkylthieno [3, 2‐b] thiophene) s—High‐Mobility Semiconductors for Thin‐Film Transistors. Adv. Mater. 2006, 18 (22), 3029-3032.
23. Pan, H.; Wu, Y.; Li, Y.; Liu, P.; Ong, B. S.; Zhu, S.; Xu, G., Benzodithiophene Copolymer—A Low‐Temperature, Solution‐Processed High‐Performance Semiconductor for Thin‐Film Transistors. Adv. Funct. Mater. 2007, 17 (17), 3574-3579.
24. Fong, H. H.; Pozdin, V. A.; Amassian, A.; Malliaras, G. G.; Smilgies, D.-M.; He, M.; Gasper, S.; Zhang, F.; Sorensen, M., Tetrathienoacene Copolymers as High Mobility, Soluble Organic Semiconductors. J. Am. Chem. Soc. 2008, 130 (40), 13202-13203.
25. Li, J.; Qin, F.; Li, C. M.; Bao, Q.; Chan-Park, M. B.; Zhang, W.; Qin, J.; Ong, B. S., High-Performance Thin-Film Transistors from Solution-Processed Dithienothiophene Polymer Semiconductor Nanoparticles. Chem. Mater. 2008, 20 (6), 2057-2059.
26. Osaka, I.; Abe, T.; Shinamura, S.; Miyazaki, E.; Takimiya, K., High-Mobility Semiconducting Naphthodithiophene Copolymers. J. Am. Chem. Soc. 2010, 132 (14), 5000-5001.
27. Rieger, R.; Beckmann, D.; Pisula, W.; Steffen, W.; Kastler, M.; Müllen, K., Rational Optimization of Benzo [2, 1‐b; 3, 4‐b′] dithiophene‐Containing Polymers for Organic Field‐Effect Transistors. Adv. Mater. 2010, 22 (1), 83-86.
28. Wang, H.; Huang, J.; Uddin, M. A.; Liu, B.; Chen, P.; Shi, S.; Tang, Y.; Xing, G.; Zhang, S.; Woo, H. Y., Cyano-Substituted Head-to-Head Polythiophenes: Enabling High-Performance n-Type Organic Thin-Film Transistors. ACS Appl. Mater. Interfaces 2019, 11 (10), 10089-10098.
29. Chen, T. A.; Rieke, R. D., The First Regioregular Head-to-Tail Poly (3-hexylthiophene-2, 5-diyl) and a Regiorandom Isopolymer: Nickel Versus Palladium Catalysis of 2 (5)-bromo-5 (2)-(bromozincio)-3-hexylthiophene Polymerization. J. Am. Chem. Soc. 1992, 114 (25), 10087-10088.
30. McCullough, R. D.; Lowe, R. D., Enhanced Electrical Conductivity in Regioselectively Synthesized Poly (3-alkylthiophenes). J. Chem. Soc., Chem. Commun. 1992, (1), 70-72.
31. Loewe, R. S.; Khersonsky, S. M.; McCullough, R. D., A Simple Method to Prepare Head‐to‐Tail Coupled, Regioregular Poly (3‐alkylthiophenes) Using Grignard Metathesis. Adv. Mater. 1999, 11 (3), 250-253.
32. Sirringhaus, H.; Brown, P.; Friend, R.; Nielsen, M. M.; Bechgaard, K.; Langeveld-Voss, B.; Spiering, A.; Janssen, R. A.; Meijer, E.; Herwig, P., Two-Dimensional Charge Transport in Self-Organized, High-Mobility Conjugated Polymers. Nature 1999, 401 (6754), 685-688.
33. Kline, R. J.; McGehee, M. D.; Kadnikova, E. N.; Liu, J.; Frechet, J. M., Controlling the Field‐Effect Mobility of Regioregular Polythiophene by Changing the Molecular Weight. Adv. Mater. 2003, 15 (18), 1519-1522.
34. Noriega, R.; Rivnay, J.; Vandewal, K.; Koch, F. P.; Stingelin, N.; Smith, P.; Toney, M. F.; Salleo, A., A General Relationship Between Disorder, Aggregation and Charge Transport in Conjugated Polymers. Nat. Mater. 2013, 12 (11), 1038-1044.
35. Mei, J.; Bao, Z., Side Chain Engineering in Solution-Processable Conjugated Polymers. Chemistry of Materials 2014, 26 (1), 604-615.
36. Russ, B.; Glaudell, A.; Urban, J. J.; Chabinyc, M. L.; Segalman, R. A., Organic Thermoelectric Materials for Energy Harvesting and Temperature Control. Nat. Rev. Mater. 2016, 1 (10), 1-14.
37. Park, Y. D.; Kim, D. H.; Jang, Y.; Cho, J. H.; Hwang, M.; Lee, H. S.; Lim, J. A.; Cho, K., Effect of Side Chain Length on Molecular Ordering and Field-Effect Mobility in Poly (3-alkylthiophene) Transistors. Org. Electron. 2006, 7 (6), 514-520.
38. Lee, H. S.; Cho, J. H.; Cho, K.; Park, Y. D., Alkyl Side Chain Length Modulates the Electronic Structure and Electrical Characteristics of Poly(3-alkylthiophene) Thin Films. J. Phys. Chem. C 2013, 117 (22), 11764-11769.
39. Bridges, C. R.; Ford, M. J.; Thomas, E. M.; Gomez, C.; Bazan, G. C.; Segalman, R. A., Effects of Side Chain Branch Point on Self Assembly, Structure, and Electronic Properties of High Mobility Semiconducting Polymers. Macromolecules 2018, 51 (21), 8597-8604.
40. Lee, M. Y.; Dharmapurikar, S.; Lee, S. J.; Cho, Y.; Yang, C.; Oh, J. H., Regular H-Bonding-Containing Polymers with Stretchability up to 100% External Strain for Self-Healable Plastic Transistors. Chem. Mater. 2020, 32 (5), 1914-1924.
41. Yao, K.; Chen, L.; Chen, X.; Chen, Y., Self-Organized Hole Transport Layers Based on Polythiophene Diblock Copolymers for Inverted Organic Solar Cells with High Efficiency. Chem. Mater. 2013, 25 (6), 897-904.
42. Wang, B.; Watt, S.; Hong, M.; Domercq, B.; Sun, R.; Kippelen, B.; Collard, D. M., Synthesis, Properties, and Tunable Supramolecular Architecture of Regioregular Poly(3-alkylthiophene)s with Alternating Alkyl and Semifluoroalkyl Substituents. Macromolecules 2008, 41 (14), 5156-5165.
43. Huang, F.; Wu, H.; Cao, Y., Water/Alcohol Soluble Conjugated Polymers as Highly Efficient Electron Transporting/Injection Layer in Optoelectronic Devices. Chem. Soc. Rev. 2010, 39 (7), 2500-2521.
44. Shao, M.; He, Y.; Hong, K.; Rouleau, C. M.; Geohegan, D. B.; Xiao, K., A Water-Soluble Polythiophene for Organic Field-Effect Transistors. Polym. Chem. 2013, 4 (20), 5270-5274.
45. Shaw, L.; Yan, H.; Gu, X.; Hayoz, P.; Weitz, R. T.; Kaelblein, D.; Toney, M. F.; Bao, Z., Microstructural Evolution of the Thin Films of a Donor–Acceptor Semiconducting Polymer Deposited by Meniscus-Guided Coating. Macromolecules 2018, 51 (11), 4325-4340.
46. Aiyar, A. R.; Hong, J. I.; Nambiar, R.; Collard, D. M.; Reichmanis, E., Tunable Crystallinity in Regioregular Poly (3‐Hexylthiophene) Thin Films and Its Impact on Field Effect Mobility. Adv. Funct. Mater. 2011, 21 (14), 2652-2659.
47. Kleinhenz, N.; Persson, N.; Xue, Z.; Chu, P. H.; Wang, G.; Yuan, Z.; McBride, M. A.; Choi, D.; Grover, M. A.; Reichmanis, E., Ordering of Poly (3-hexylthiophene) in Solutions and Films: Effects of Fiber Length and Grain Boundaries on Anisotropy and Mobility. Chem. Mater. 2016, 28 (11), 3905-3913.
48. McBride, M.; Persson, N.; Keane, D.; Bacardi, G.; Reichmanis, E.; Grover, M. A., A Polymer Blend Approach for Creation of Effective Conjugated Polymer Charge Transport Pathways. ACS Appl. Mater. Interfaces 2018, 10 (42), 36464-36474.
49. Bielecka, U.; Lutsyk, P.; Janus, K.; Sworakowski, J.; Bartkowiak, W., Effect of Solution Aging on Morphology and Electrical Characteristics of Regioregular P3HT FETs Fabricated by Spin Coating and Spray Coating. Org. Electron. 2011, 12 (11), 1768-1776.
50. Chang, M.; Choi, D.; Fu, B.; Reichmanis, E., Solvent Based Hydrogen Bonding: Impact on Poly (3-hexylthiophene) Nanoscale Morphology and Charge Transport Characteristics. ACS nano 2013, 7 (6), 5402-5413.
51. Chang, M.; Lee, J.; Kleinhenz, N.; Fu, B.; Reichmanis, E., Photoinduced Anisotropic Supramolecular Assembly and Enhanced Charge Transport of Poly (3‐hexylthiophene) Thin Films. Adv. Funct. Mater. 2014, 24 (28), 4457-4465.
52. Yuan, Y.; Giri, G.; Ayzner, A. L.; Zoombelt, A. P.; Mannsfeld, S. C. B.; Chen, J.; Nordlund, D.; Toney, M. F.; Huang, J.; Bao, Z., Ultra-High Mobility Transparent Organic Thin Film Transistors Grown by an Off-centre Spin-Coating Method. Nat. Commun. 2014, 5 (1), 3005.
53. Sim, K.; Rao, Z.; Kim, H.-J.; Thukral, A.; Shim, H.; Yu, C., Fully Rubbery Integrated Electronics from High Effective Mobility Intrinsically Stretchable Semiconductors. Sci. Adv. 2019, 5 (2), eaav5749.
54. Peeters, H.; Couturon, P.; Vandeleene, S.; Moerman, D.; Leclère, P.; Lazzaroni, R.; De Cat, I.; De Feyter, S.; Koeckelberghs, G., Influence of The Regioregularity on the Chiral Supramolecular Organization of Poly (3-alkylsulfanylthiophene)s. RSC Adv. 2013, 3 (10), 3342-3351.
55. Wang, P.; Jeon, I.; Lin, Z.; Peeks, M. D.; Savagatrup, S.; Kooi, S. E.; Van Voorhis, T.; Swager, T. M., Insights into Magneto-Optics of Helical Conjugated Polymers. J. Am. Chem. Soc. 2018, 140 (20), 6501-6508.
56. Huo, L.; Zhou, Y.; Li, Y., Alkylthio‐Substituted Polythiophene: Absorption and Photovoltaic Properties. Macromol. Rapid Commun. 2009, 30 (11), 925-931.
57. Cui, C.; Wong, W.-Y.; Li, Y., Improvement of Open-Circuit voltage and Photovoltaic Properties of 2D-Conjugated Polymers by Alkylthio Substitution. Energy Environ. Sci. 2014, 7 (7), 2276-2284.
58. Bin, H.; Zhang, Z.-G.; Gao, L.; Chen, S.; Zhong, L.; Xue, L.; Yang, C.; Li, Y., Non-Fullerene Polymer Solar Cells Based on Alkylthio and Fluorine Substituted 2D-Conjugated Polymers Reach 9.5% Efficiency. J. Am. Chem. Soc. 2016, 138 (13), 4657-4664.
59. Li, R.; Zhang, X.; Zhu, P.; Ng, D. K.; Kobayashi, N.; Jiang, J., Electron-Donating or-Withdrawing Nature of Substituents Revealed by the Electrochemistry of Metal-Free Phthalocyanines. Inorg. Chem. 2006, 45 (5), 2327-2334.
60. Spano, F. C.; Silva, C., H-and J-Aggregate Behavior in Polymeric Semiconductors. Annu. Rev. Phys. Chem. 2014, 65, 477-500.
61. Clark, J.; Chang, J.-F.; Spano, F. C.; Friend, R. H.; Silva, C., Determining Exciton Bandwidth and Film Microstructure in Polythiophene Films Using Linear Absorption Spectroscopy. Appl. Phys. Lett. 2009, 94 (16), 117.