• Electrical & Electronic Materials
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• v.9 no.2
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• pp.165-173
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• 1996

We prepared polythiophene and poly(3-methylthiophene) films, known as conducting polymer, by electrochemical method. Polythiophene and poly(3-methylthiophene) films were doped and undoped dopant for the studing the understanding of doping mechanism and possible application to the color change switch. We observed that the anodic, cathodic wave and absorption spectra were slightly changed during doping and undoping process in polythiophene. It shows that doping and undoping process were showed some difference by the appearance and disappearance of polaron and bi-polaron. In the relation of the peak of oxidative current density and potential sweep rate of cyclic voltammograms, the amount of dopant in polythiophene film was homogeneously increased at low scan rate. This also can be applied to the poly(3-methlythiophene).

• Current Photovoltaic Research
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• v.6 no.4
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• pp.91-93
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• 2018

Polythiophene-$TiO_2$ composite was synthesized with different molar ratios of thiophene and titaniumisopropoxide ($Ti(OPr)_4$) for flexible solar cell application as a flexible electrode or an active material. The $Ti(OPr)_4$ was stabilized by thiophene. The thiophene was polymerized by ferric chloride catalyst. The synthesized polythiophene exhibited strong UV-visible absorption in the range of the wavelength shorter than 500 nm. Field emission scanning electron microscope (FESEM) image of low concentration of $TiO_2$ film showed smooth surface. However, FESEM image of high concentration of $TiO_2$ film exhibited relatively rough surface. Polythiophene concentration dependent strong photoluminescence quenching of surfrhodamine-B was observed.

• Electrical & Electronic Materials
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• v.5 no.3
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• pp.337-343
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• 1992

FeCl$_{3}$등 천이금속 halides를 촉매로 이용하여 poly(3-hexylthiophene) 등의 가용성 polythiophene 유도체를 합성하였다. casting에 의해 작성한 필림은 전해중합 법에 의한 polythiophene 필림과 같은 특성을 나타낸다. Poly(3-hexylthiophene)의 용액 상태의 에너지 밴드 갭은 2.42(eV)이며 이것은 필림상태 보다 고분자 쇄간의 상호작용이 약하므로 밴드 갭이 더 크다. 또한 I$_{2}$를 도우프하면 고차 구조가 달라지므로 poly(3-hexylthiophene)은 polythiophene 보다 도핑속도가 더욱 빠르다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.573-576
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• 2001

In the research fields of energy storage, and more specifically of supplying high powers, electrochemical supercapacitor have been among the most studied systems for many years. One of the possible applications is in electric vehicles. We have been working on electronically conducting polymers for use as active materials for electrodes in supercapacitors. These polymers have the ability of doping and undoping with rather fast kinetics and have an excellent capacity for energy storage. polythiophene (Pth) and polyparafluorophenylthiophene (PFPT) have been chemically synthesized for use as active materials in supercapacitor electrodes. Electrochemical characterization has been performed by cyclic voltammetry and an electrode study has been achieved to get the maximun capacity out of the polymers and give good cyclability. specific capacity values of 7mAh/g and 40mAh/g were obtained for PFPT and polythiophene, respectively. Supercapacitors have been built to characterize this type of system. Energy storage levels of 260F/g were obtained with Pth and 110F/g with PFPT

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.04a
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• pp.127-129
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• 1997

The high pretilt angles in nematic liquid crystals (NLCs) have been generated on robbed polythiophene (PTP) surfaces with alkyl chain lengths. The pretilt angle of the NLC was observed on unidirectionally rubbed PTP surfaces with alkyl chains with more than 9 carbon atoms. We obtained the Pretilt angle of 15~40$^{\circ}$ on rubbed PTP surfaces with 10 carbon atoms in the a1ky1 chain. Also, the pretilt angles of 65~80$^{\circ}$ of NLC were obtained on rubbed PTP surfaces with 11 and 12 carbon atoms in the alkyl chain. We suggest that this high pretilt angle generation in NLC is due to the surface-excluded volume effect by the alkyl chain lengths between. the LCs and the PTP surfaces. Finally, we conclude the odd-even effect on rubbed PTP surfaces is clearly contributed to the pretilt angle generation.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.286-286
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• 2006

We report on a fascinating morphology; giant spherical conducting polythiophene by the in-situ gamma radiation-induced chemical polymerization method. The resultant micron-size buckyball-shaped polymer structures were identified by high resolution transmission electron microscopy and scanning electron microscopy. Different characterizations e.g. Fourier transform infrared, x-ray diffraction, and x-ray photoelectron microscopy were utilized to prove that the new morphological conducting polythiophene was synthesized successfully by this novel method.

• Proceedings of the Korean Fiber Society Conference
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• 2003.04a
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• pp.305-306
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• 2003

전기전도성 고분자는 금속과 유사한 전도성을 가진 공액이중결합의 고분자로서, 전기적, 전기 화학적, 광학적 성질 둥을 가지고 있어 그 연구 범위가 넓으며, 지금까지 많은 연구 논문들이 보고 되어왔으며 최근에는 전도성(Conducting) 유기물질들과 반도체(Semiconducting) 유기물질들이 electrolumine- scent diodes, membranes, 재충전 batteries와 같은 장치에 응용되고 있다[1]. 대표적인 전기전도성 고분자로는 polyacetylene, poly(p-phenylene), polyaniline, polypyrrole, polythiophene 등이 있고 특히 그 중에서 전도성과 stability가 우수한 polypyrrole과 polythiophene에 관한 많은 연구가 진행되어 왔다[2]. (중략)

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.573-576
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• 2001

In the research fields of energy storage, and more specifically of supplying high powers, electrochemical supercapacitor have been among the most studied systems for many years. One of the possible applications is in electric vehicles. We have been working on electronically conducting polymers for use as active materials for electrodes in supercapacitors. These polymers have the ability of doping and undoping with rather fast kinetics and have an excellent capacity for energy storage. polythiophene (Pth) and polyparafluorophenylthiophene (PFPT) have been chemically synthesized for use as active materials in supercapacitor electrodes. Electrochemical characterization has been performed by cyclic voltammetry and an electrode study has been achieved to get the maximun capacity out of the polymers and give good cyclability. specific capacity values of 7mAh/g and 40mAh/g were obtained for PFPT and poly thiophene, respectively. Supercapacitors have been built to characterize this type of system. Energy storage levels of 260F/g were obtained with Pth and 110F/g with PFPT.

• Rapid Communication in Photoscience
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• v.2 no.3
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• pp.79-81
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• 2013

A novel method of fabricating polythiophene-gold nanoparticle composite film electrodes for photoelectric conversion is demonstrated. The method includes electrodeposition of gold and electropolymerization of 2,2'-bithiophene onto an indium-tin-oxide (ITO) electrode. First, electrodeposition of gold onto the ITO electrode was carried out with various repetition times of pulsed applied potential (0.25 s at -2.0 V vs. Ag/AgCl) in an aqueous solution of $HAuCl_4$. Significant progress of the number density of deposited gold nanoparticles was confirmed from scanning electron micrographs, from 4 (1 time) to 25% (15 times). Next, electropolymerization of 2,2'-bithiophene onto the above ITO electrode was performed under controlled charge condition (+1.4 V vs. Ag wire, 15 $mC/cm^2$). Structural characterization of as-fabricated films were carried out by spectroscopic and electron micrographic methods. Photocurrent responses from the sample film electrodes were investigated in the presence of electron acceptors (methyl viologen and oxygen). Photocurrent intensities increased with increasing the density of deposited gold nanoparticles up to ~10%, and tended to decrease above it. It suggests that the surplus gold nanoparticles exhibit quenching effects rather than enhancement effects based on localized electric fields induced by surface plasmon resonance of the deposited gold nanoparticles.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.12 no.1
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• pp.69-74
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• 1999

We have investigated that the high pretilt angle of the NLC, 4-n-pentyl-4-cyanobiphenyl (5CB), was observed on rubbed polythiophene (PTP) surfaces with alkyl chains with more than 10 carbon atoms; it is attributed to the surface-excluded volume effect by the alkyl chain lengths between the LCs and the PTP surfaces. Next, we investigated that the odd-even effect of the polar anchoring strength in 5CB on rubbed PTP surfaces with alkyl chain lengths has been successfully evaluated. The anchoring strength of 5CB for rubbed PTP surfaces with odd-number is weak compared with even-number up to the 6 carbon atoms in the alkyl chain; however, odd-number is strong compared with even-number above 7 carbon atoms. The weak anchoring strength of 5CB is approximately $1\times10^{-3} (J/m^2$) on rubbed PTP surface with 7 carbon atoms; it is relatively strong anchoring strength. Consequently, we conclude that the odd-even effects of the polar anchoring strength in NLCs are strongly related to the characteristics of the polymer and observed clearly for short alkyl chain lengths.