本論文研究以高立體規則度高分子半導體poly(3-hexylthiophene)
(RR-P3HT)為主動層之有機薄膜電晶體電特性。本論文分為三個部份，第一部分，利用不同溶劑配製不同濃度RR-P3HT 溶液並製備薄膜，研究溶液濃度對元件電特性的影響；第二部份，研究RR-P3HT 有機薄膜電晶體操作時的遲滯效應，於不同溫度進行元件電特性量測，探討變溫量測對元件遲滯效應的影響；第三部份，進行高分子覆蓋層對RR-P3HT 元件電特性的影響研究。
第一部份，使用不同溶劑製備RR-P3HT 溶液，包含四種溶劑
1,2,4-Trichlorobenzene、p-xylene、toluene、chloroform，利用旋轉塗佈法製作薄膜，研究RR-P3HT 薄膜從未成膜至成膜後的結構差異，利用拉曼光譜與吸收光譜分別研究RR-P3HT 的分子振動特性與薄膜結構，研究溶劑種類與溶液濃度對RR-P3HT 薄膜結構的影響，並探討與電特性的相關性。實驗結果發現當濃度為0.34 wt%時，使用高沸點溶劑製成RR-P3HT薄膜有較佳的分子鏈間的接觸，因此電性較佳，然而使用較高濃度時，RR-P3HT 形成較多聚集態，因而導致結構缺陷，不利電荷傳輸，電性較差。
第二部份，研究元件量測溫度對RR-P3HT 薄膜電晶體元件電特性的
影響，量測溫度由室溫27 度到117 度。於高溫下，RR-P3HT 元件有較嚴重的遲滯效應，可解釋為當溫度上升半導體層內電荷陷阱之生命週期變長所致。使用沸點較低的溶劑所製作的元件，遲滯效應更嚴重，由第一部份的吸收光譜發現四種溶劑製成的薄膜中以chloroform 為溶劑的RR-P3HT 薄膜在有較差的分子間接觸，所以當量測溫度上升時半導體層內電荷陷阱增多，導致遲滯現象遠大於其他三種溶劑製成的元件。
第三部份，研究有機薄膜電晶體的最上方旋轉塗佈上一層高分子覆
蓋層，討論高分子覆蓋層對不同溶劑製成元件電特性的變化，本章節高分子覆蓋層使用的是三種常見高分子絕緣材料poly(vinyl pyrrolidone)(PVnP)、polymethylmethacrylate(PMMA)、poly(vinylidene fluoride)(PVDF)，RR-P3HT 使用chloroform 為溶劑製成的元件上方旋轉塗佈一層PMMA 或PVDF 之高分子覆蓋層時，其元件的飽和區場效載子遷移率提高，RR-P3HT 使用其他溶劑製成的元件在覆蓋上高分子覆蓋層以後載子遷移率呈現一個下降的狀態，歸因於半導層遭到覆蓋層溶液造成傷害。用這三種高分子材料做覆蓋層時，RR-P3HT 使用chloroform 為四種溶劑中對半導體層傷害最小的，能有效的讓高分子覆蓋層保護半導體層。

In this study, we studied the thin-film structures and electronic transport properties of regioregular poly(3-hexylthiophene) (RR-P3HT) films in organic thin-films transistors(OTFTs).The RR-P3HT films were prepared by solution deposition through a spin-coating technique using several different solvents which have different boiling points.In part 1, the effects of solvent concentration on the preparation of RR-P3HT films and on the electrical
properties of OTFTs were investigated. In part 2, the influence of measuring temperature on the hysteresis effects of RR-P3HT-based OTFTs was studied. In part 3, we studied the impact of the polymeric passivation layer on the electrical properties of RR-P3HT-based OTFTs.
In part 1, we studied the solvent effects on the electrical characteristics of RR-P3HT-based OTFTs, including four organic solvents: p-xylene, 1,2,4-trichlorobenzene (TCB), toluene, and chloroform. The formation behavior and structure of RR-P3HT films formed were analyzed by micro-Raman Spectroscopy and UV-Vis absorption spectroscopy. We found that when the high boiling point solvent, i.e. TCB, is used to dissolve the
RR-P3HT in a dilute solvent concentration of 0.34 wt%, the obtained solid films have better interchain contact, thus device performance. When higher solvent concentrations
were used, we observed that the OTFTs show inferior electrical characteristics due to the RR-P3HT films containing more aggregate states and structural defects.
In part 2, we investigated the influence of measuring temperatures from 27 to 117 ℃ on the device characteristics of RR-P3HT-based OTFTs. Under high temperature measurements, the devices suffered from serious hysteresis effects and attributed to the increased lifetime of charge in trap states within the RR-P3HT-based OTFTs. Moreover, enhanced hysteresis effects are seen in devices in which the RR-P3HT films are prepared by using low boiling point organic solvents, e.g. chloroform. We interpret this phenomenon in terms of the RR-P3HT interchain contact and films quality.
In part 3, we studied the effects of the passivation layer on the performance of RR-P3HT-based OTFTs using three kinds of polymeric layers: poly(vinyl pyrrolidne)
(PVnP), polymethylmethacrylate (PMMA), and poly(vinylidene fluoride) (PVDF). The PVnP, PMMA, and PVDF passivation layers were prepared by solution deposition through a spin-coating method using the following solvents: water, p-xylene, and N,N-dimethylformamide (DMF), respectively. In the OTFTs with P3HT films using chloroform the increase in the on-current and mobility was significant when PMMA and
PVDF were used as a passivation layer. When other solvents were used for preparing RR-P3HT-based OTFTs, there was degradation in the performance of the OTFT when these polymeric passivation layers were used, a result of the damage to the RR-P3HT active layer by the organic solvent in PVnP, PMMA, and PVDF solutions. The results revealed that chloroform used as a solvent to prepare RR-P3HT film can minimize the damage to the active layer of OTFTs and prevent the penetration of the organic solvent in a
solution of passivation polymers.

[1] C. W. Tang and S. A. VanSlyke, “Organic electroluminescent diodes”
Appl. Phys. Lett. 51, p.913, 1987.
[2] J. H. Burroughes, D. D. Bradley, A. R. Brown, R. N. Marks, K. Mackay,
R. H. Friend, P. L. Burn and A. B. Holmes, “Light-emitting diodes based
on conjugated polymers” Nature, 347, p.539, 1990.
[3] F. Ebisawa, T. Kurokawa and S. Nara, “Electrical properties of
polyacetylene/polysiloxane interface” J. Appl. Phys. 54, p.3255, 1983.
[4] A. Tsumura, H. Koezuka and T. Ando, “Macromolecular electronic
device: field-effect transistor with a polythiophene thin film” Appl. Phys.
Lett. 49, p.1210, 1986.
[5] W. Riess, S. Karg, V. Dyakonov, M. Meier and M. Schwoerer,
“Electroluminescence and photovoltaic effect in PPV schottky diodes” J.
Lumine. 60, p.906, 1994.
[6] N. S. Sariciftci, D. Braun, C. Zhang, V. I. Srdanov, A. J. Heeger, G.
Stucky and F. Wudl, “Semiconducting polymer-buckminsterfullerene
heterojunctions: Diodes, photodiodes, and photovoltaic cells” Appl. Phys.
Lett. 62, p.585, 1993.
[7] Y. Sun, Y. Liu and D. Zhu, “Advances in organic field-effect
transistors” J. Mater. Chem. 15, p.53, 2005.
[8] A. Facchetti, “Semiconductors for organic transistors” materialstoday 10,
p28, 2007.
[9] S. M. Sze, “Semiconductor Devices：Physics and technology 2nd edition”
John Wiley & Sons INC., New York, 2001.
[10] M. J. Panzer and C. D. Frisbie, “High Carrier Density and Metallic
Conductivity in Poly(3-hexylthiophene) Achieved by Electrostatic
Charge Injection” Adv. Funct. Mater. 16, p.1051, 2006.
[11] Z. Bao, A. Dodabalapur and A. J. Lovinger, “Soluble and processable
regioregular poly(3-hexylthiophene) for thin film field-effect transistor
applications with high mobility” Appl. Phys. Lett. 69, p.4108, 1996.
[12] J. F. Chang, B. Sun, D. W. Breiby, M. M. Nielsen, T. I. Solling, M.
Giles, I. McCulloch and H. Sirringhaus, “Ehanced mobility of
poly(3-hexylthiophene) transistors by spin-coating from
high-boiling-point solvents.” Chem. Mater. 16, p.4772, 2004.
[13] M. J. Joung, C. A. Kim, S. Y. Kang, Kyu-Ha Beak, G. H. Kim, S. D.
Ahn, I. K. You, J. H. Ahn and K. S. Suh, “The application of soluble and
regioregular poly(3-hexylthiophene) for organic thin-film transistors”
Synth. Met. 149, p.73, 2005.
[14] 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. Herwing and D. M. de Leeuw,
“Two-dimensional charge transport in self-organized, high-mobility
conjugated polymers” Nature, 401, p.685, 1999.
[15] H. Sirringhaus, N. Tessler and R. H. Friend, “Integrated optoelectronic
devices based on conjugated polymers” Science, 280, p.1741, 1998.
[16] G. Wang, T. Hirasa, D. Moses and A. J. Heeger, “Fabrication of
regioregular poly(3-hexylthiophene) field-effect transistors by
dip-coating” Synth. Met. 146, p.127, 2004.
[17] H. Sirringhaus, N. Tessler, R. H. Friend, “Integrated, high-mobility
polymer field-effect transistors driving polymer light-emmiting diodes”
Synth. Met. 102, p.857, 1999.
[18] H. Sirringhaus, P. J. Brown, R. H. Friend, M. M. Nielsen, K. Bechgaard,
B. M. W. Lgeveld-Voss, A. J. H. Spiering, R. A. J. Janssen and E. W.
Meijer, “Microstructure–mobility correlation in self-organised,
conjugated polymer field-effect transistors” Synth. Met. 111-112, p.129,
2000.
[19] G. Wang, J. Swensen, D. Moses and A. J. Heeger, “Increased mobility
from regioregular poly(3-hexylthiophene)field-effect transistors” J. Appl.
Phys. 93, p.6171, 2003.
[20] G. Lloyd, M. Raja, I. Sellers, N. Sedghi, R. D. Lucrezia, S. Higgins, B.
Eccleston, “The properties of MOS structures using conjugated polymers
as the semiconductor” Microelectronic Engineering, 59, p.323, 2001.
[21] D. H. Kim, Y. D. Park, Y. Jang, H. Yang, Y. H. Kim, J. I. Han, K. G.
Moon, S. Park, T. Chang, C. Chang, M. Joo and C. Y. Ryu,
“Enhancement of Field-Effect Mobiliuty Due to Surface-Mediated
Molecular Ordering in regioregular poly(3-hexylthiophene) field-effect
transistors” Adv. Funct. Mater. 15, p.77, 2005.
[22] M. Surin, P. Leclere, R. Lazzaroni, J. D. Yuen, G. Wang, D. Moses, A. J.
Heeger, S. Cho, K. Lee, “Relationship between the microscopic
morphology and the charge transport properties in poly(3-hexylthiophene)
field-effect transistors” J. Appl. Phys. 100, p.0033712, 2006.
[23] B. S. Ong, Y. Wu, P. Liu and S. Gardner, ”High-performance
semiconducting polythiophenes for organic thin-film transistors” J. Am.
Chem. Soc. 126, p.3378, 2004.
[24] R. J. Kline, M. D. McGehee, E. N. Kadnikova, J. Liu and J. M. J.
Frechet, Adv. Mater. 15, p.1519, 2003.
[25] G. Wang, T. Hirasa, D. Moses and A. J. Heeger, “Fabrication of
regioregular poly(3-hexylthiophene) field-effect transistors by
dip-coating” Synth. Met. 146, p.127, 2004.
[26] H. Yang, T. J. Shin, L. Yang, K. Cho, C. Y. Ryu and Z. Bao, “Effect
ofmesoscale crystalline structure on the field-effect mobility of
regioregular poly(3-hexyl thiophene) in thin-film transistors” Adv. Funct.
Mater. 15, p.671, 2005.
[27] T. A. Chen, X. Wu and R. D. Rieke, “Regiocontrolled synthesis of
poly(3-alkylthiophenes) mediated by rieke zinc: their characterization and
solid-state properties” J. Am. Chem. Soc. 117, p.233, 1995.
[28] G. Louarn, M. Trznadel, J. P. Buisson, J. Laska, A. Pron, M. Lapkowski
and S. Lefrant, “Raman spectroscopic studies of regioregular
poly(3-alkylthiophenes)” J. Phys. Chem. 100, p.12532, 1996.
[29] S. Lefrant, I. Baltog, M. Lamy de Chapelle, M. Baibarac, G. Louarn, C.
Journet and P. Bernier, “Structural properties of some
conductingpolymers and carbon nanotubes investigated by SERS
spectroscopy” Synth. Met. 100, p.13, 1999.
[30] M. Baibarac, M. Lapkowski, A. Pron, S. Lefrant, I. Batlog,
“SERSspectra of poly(3-hexylthiophene) in oxidized and unoxidized
states” J. Raman Spectrosc, 29, p.825, 1998.
[31] G. Zerbi, B. Chierichetii, O. Inganas, “Thermochromism
inpolyalkylthiophenes: molecular aspects from vibrational spectroscopy”
J. Chem. Phys. 97, p.4646, 1991
[32] P. J. Brown, D. S. Thomas, A. Kohler, J. S. Wilson, J. Kim, C. M.
Ramsdale, H. Sirringhaus, and R. H. Friend, “Effect of interchain
interactions on the absorption and emission of poly.3-hexylthiophene”
Phys. Rev. B, 67, p.064203, 2003.
[33] G. Wang, J. Swensen, D. Moses, and A. J. Heeger, “Increased mobility
from regioregular poly(3-hexylthiophene) field effect transistor” J. Appl.
Phys. 93 p.6137, 2003.
[34] G. H. Gelinck, T. C. T. Geuns and D. M. de Leeuw, “High-performance
all-polymer integrated circuits” Appl. Phys. Lett. 77, p.1487, 2000.
[35] B. Crone, A. Dodabalapur, Y. Y. Lin, R. W. Filas, Z. Bao, A. LaDuca, R.
Sarpeshkar, H. E. Katz and W. Li, “Large-scale complementary
integrated circuits based on organic transistors” Nature, 403, p.521, 2000.
[36] C. J. Drury, C. M. J. Mutsaers, C. M. Hart, M. Matters and D. M. de
Leeuw, “Low-cost all-polymer integrated circuits” Appl. Phys. Lett. 73,
p.108, 1998.
[37] J. R. Sheats, “Manufacturing and commercialization issues in organic
electronics” J. Mater. Res. 19, p.1974, 2004.
[38] P. F. Baude, D. A. Ender, M. A. Haase, T. W. Kelley, D. V. Muyres, S.
D.Thesis, “Pentacene-based radio-frequency identification circuitry” Appl.
Phys. Lett. 82, p.3964, 2003.
[39] T.W. Kelley, P.F. Baude, C. Gerlach, D.F. Ender, D. Muyres, M. A.
Haase, D.E. Vogel and S.D. Theiss, “Recent progress in organic
electronics: materials, devices, and processes” Chem. Mater. 16, p.4413,
2004.
[40] W. Clemens, W. Fix, J. Ficker, A. Knobloch, A. Ullmann, “From
polymer transistors toward printed electronics” J. Mater. Res. 19, p.1963,
2004.
[41] B. Crone, A. Doadbalapur, A. Gelperin, L. Torsi, H.E. Katz, A.J.
Lovinger and Z. Bao, “Electronic sensing of vapors with organic
transistors” Appl. Phys. Lett. 78, p.2229, 2001.
[42] L. Torsi, N. Cioffi, C.D. Franco, L. Sabbatini, P.G. Zambonin, T.
Bleve-Zacheo, “Organic thin film transistors: from active materials to
novel applications” Solid-State Electron. 45, p.1479, 2001.
[43] T. Someya, T. Sekitani, S. Iba, Y. Kato, H. Kawaguchi and T. Sakurai,
“A large-area, flexible pressure sensor matrix with organic field-effect
transistors for artificial skin applications” Proc. Natl. Acad. Sci. 101,
p.9966, 2004.
[44] J. A. Rogers, Z. Bao and A. Dodabalapur, “Organic smart pixels and
complementary inverter circuits formed on plastic substrates by casting
and rubber stamping” IEEE Electron Device Lett. 21, p.100, 2000.
[45] P. Mach, S.J. Rodriguez, R. Nortrup, P. Wiltiuz and J.A. Rogers,
“Monolithically integrated, flexible display of polymer-dispersed liquid
crystal driven by rubber-stamped organic thin-film transistors” Appl.
Phys.Lett. 78, p.3592, 2001.
[46] C.D. Sheraw, L. Zhou, J.R. Huang, D.J. Gunbdlich, T.N. Jackson,M.G.
Kane, I.G. Hill, M.S. Hammond, J. Campi, B.K. Greening, J. Francl and J.
West, “Organic thin-film transistor-driven polymer-dispersed liquid
crystal displays on flexible polymeric substrates” Appl. Phys. Lett. 80,
p.1088, 2002.
[47] Y. H. Kim, S. K. Park, D. G. Moon, W. K. Kim and J. I. Han,
“Active-matrix liquid crystal display using solution-based organic thin
film transistors on plastic substrates” Displays 25, p.167, 2004.
[48] B. Comiskey, J. D. Albert, H. Yshizawa and J. Jacobson, “An
electrophoretic ink for all-printed reflective electronic displays” Nature,
394, p.253, 1998.
[49] C. D. Dimitrakopuls and D. J. Mascaro, “Organic thin-film transistors:
A review of recent advances” IBM J. Res. Develop. 45, p.11, 2001.
[50] S. K. Park, Y. H. Kim, J. I. Han, D. G. Moon,W. K. Kim and M. G.
Kwak, “Electrical characteristics of poly (3-hexylthiophene) thin film
transistors printed and spin-coated on plastic substrates” Synth. Met. 139,
p.377, 2003.
[51] M. M. Ling and Z. Bao, “Thin film deposition, patterning, and printing
in organic thin film transistors” Chem. Mater. 16, p.4824, 2004.
[52] G. Gu, M. G. Kane, J. E. Doty and A. H. Firester, ”Electron traps and
hysteresis in pentacene-based organic thin-film transistors” Appl. Phys.
Lett. 87, p.243512, 2005.
[53] H. Rost, J. Ficker, J.S. Alonso, L. Leenders and I. McCulloch,
“Air-stable all-polymer field-effect transistors with organic electrodes”
Synth. Met. 145, p.83, 2004.
[54] J. Kanicki, C. Martin, in: C.R. Kagan and P. Andry (Eds.), “Thin-film
transistor” Marcel dekker, New York, USA, p.118, 2004.
[55] C. A. Lee, D. W. Park, S. H. Jin, I. H. Park, J. D. Lee, and B. G. Park,
“Hysteresis mechanism and reduction method in the bottom-contact
pentacene thin-film transistors with cross-linked poly(vinyl alcohol)gate
insulator” Appl. Phys. Lett. 88, p.252102, 2006.
[56] S. C. Lim, S. H. Kim, J. B. Koo, J. H. Lee, C. H. Ku, Y. S. Yang, and T.
Zyung, “Hysteresis of pentacene thin-film transistors and inverters with
cross-linked poly(4-vinylphenol) gate dielectrics” Appl. Phys. Lett. 90,
p.173512, 2007.
[57] S. E. Fritz, T. W. Kelley, and C. D. Frisbie, “Effect of Dielectric
Roughness on Performance of Pentacene TFTs and Restoration of
Performance with a Polymeric Smoothing Layer” J. Phys. Chem. B 109,
p.10574, 2005.
[58] R.C.G. Naber, M. Mulder, B. de Boer, P.W.M. Blom, and D.M. de
Leeuw,“High charge density and mobility in poly(3-hexylthiophene)
using a polarizable gate dielectric”Org. Electron. 7, p.132, 2006.
[59] M. Estrada, I. Mejia, A. Cerdeira, and B. In˜iguez,“MIS polymeric
structures and OTFTs using PMMA on P3HT layers” Solid-State
Electronics. 52, p.53, 2008.
[60] J. Zaumseil, C. L. Donley, J. S. Kim, R. H. Friend, and H.
Sirringhaus,“Efficient Top-Gate, Ambipolar, Light-Emitting Field-Effect
Transistors Based on a Green-Light-Emitting Polyfluorene” Adv. Mater.
18, p.2708, 2006.
[61] H. G. O. Sandberg, T. G. Bäcklund, R. Österbacka, and H.
Stubb,“High-performance All-polymer Transistor Utilizing a
Hygroscopic Insulator” Adv. Mater. 16, 13, p.1112, 2004.
[62] T. G. Bäcklund, R. Österbacka, H. Stubb, J. Bobacka and A.
Ivaska,“Operating principle of polymer insulator organic thin-film
transistors exposed to moisture” J. Appl. Phys. 98, p.74504, 2005.
[63] H. G.O. Sandberg, T. G. Ba¨cklund, R. O¨ sterbacka, M. Shkunov, D.
Sparrowe, I. McCulloch, and H. Stubb, “Insulators and device geometry
in polymer field effect transistors” Org. Electron. 6, p.421, 2005.