• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.479-479
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• 2011

Flexible inverters based on complementary thin-film transistor (CTFTs) are important because they have low power consumption and other advantages over single type TFT inverters. In addition, integrated CTFTs in flexible electronic circuits on low-cost, large area and mechanically flexible substrates have potentials in various applications such as radio-frequency identification tags (RFIDs), sensors, and backplanes for flexible displays. In this work, we introduce flexible complementary inverters using pentacene and amorphous indium gallium zinc oxide (IGZO) for the p-channel and n-channel, respectively. The CTFTs were fabricated on polyimide (PI) substrate. Firstly, a thin poly-4-vinyl phenol (PVP) layer was spin coated on PI substrate to make a smooth surface with rms surface roughness of 0.3 nm, which was required to grow high quality IGZO layers. Then, Ni gate electrode was deposited on the PVP layer by e-beam evaporator. 400-nm-thick PVP and 20-nm-thick ALD Al2O3 dielectric was deposited in sequence as a double gate dielectric layer for high flexibility and low leakage current. Then, IGZO and pentacene semiconductor layers were deposited by rf sputter and thermal evaporator, respectively, using shadow masks. Finally, Al and Au source/drain electrodes of 70 nm were respectively deposited on each semiconductor layer using shadow masks by thermal evaporator. Basic electrical characteristics of individual transistors and the whole CTFTs were measured by a semiconductor parameter analyzer (HP4145B, Agilent Technologies) at room temperature in the dark. Performance of those devices then was measured under static and dynamic mechanical deformation. Effects of cyclic bending were also examined. The voltage transfer characteristics (Vout- Vin) and voltage gain (-dVout/dVin) of flexible inverter circuit were analyzed and the effects of mechanical bending will be discussed in detail.

• Transactions on Electrical and Electronic Materials
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• 제9권6호
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• pp.247-250
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• 2008

Hafnium dioxide ($HfO_2$) thin film as a gate dielectric for organic thin film transistors is prepared by plasma enhanced atomic layer deposition (PEALD). Mostly crystalline of $HfO_2$ film can be obtained with oxygen plasma and with water at relatively low temperature of $200^{\circ}C$. $HfO_2$ was deposited as a uniform rate of $1.2\;A^{\circ}$/cycle. The pentacene TFT was prepared by thermal evaporation method with hafnium dioxide as a gate dielectric. The electrical properties of the OTFT were characterized.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
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• pp.72-73
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• 2009

In this study, we fabricated of pentacene organic thin film trasistor(OTFT), which used aluminum oxide for the gate insulator on glass substrate. Aluminum oxide for OTFTs was deposited on the gate layer by E-beam evaporation. aluminum oxide fabricated various deposition rate. In this case of the deposition rate of $0.1\;{\AA}$, the fabricated aluminum oxide gate insulator OTFT showed a threshold voltage of -1.36V, an on/off current ratio of $1.9{\times}l0^3$ and field effect mobility $0.023\;cm^2/V_s$.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.61-62
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• 2011

본 논문에서는 top-contact 구조의 유기 박막 트랜지스터를 이용하여 정류기와 인버터를 제작하고 전기적 특성을 분석 하였다. 게이트 절연막으로는 PMMA (polymethyl methacrylate)를 사용하였고 유기물 활성층으로 pentacene을 진공 증착하여 사용하였다. 유기 박막 트랜지스터로 제작된 정류기는 약 3 V의 DC 전압을 얻어 39 %의 효율특성을 보였고, 인버터는 1.2의 이득값을 얻어 유기전자회로의 실용 가능성을 확인 하였다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1166-1169
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• 2006

In this study, the effects of SAMs on the performance of OTFTs have been investigated. ALD technique was applied for the deposition of SAMs, which is an ultra-thin film deposition technique based on sequences of self-limiting surface reactions enabling thickness control on atomic scale. According to our investigation results, it is observed that the surface properties of the gate insulator was changed by SAMs, which allow pentacene molecules to be deposited in the upright direction on the gate insulator and hence the performance of OTFTs could be improved. These results will be discussed

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1170-1173
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• 2006

Active layer patterned OTFT was obtained on a plastic substrate using the optimal growth condition of pentancene thin films as active layer and parylene thin films as passivation layer. Tranditional photolithography was performed to use a dry etch to pattern the material stack. The pentacene thin film and parylene thin film were deposited onto a plastic substrate using PC-OVD and CVD, respectively.

• Journal of Information Display
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• 제12권4호
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• pp.213-217
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• 2011

Printing technologies were applied to fabricate a flexible organic thin-film transistor (OTFT) backplane for electrophoretic displays (EPDs). Various printing processes were adopted to maximize the figures of each layer of OTFT: screen printing combined with reverse offset printing for the gate electrodes and scan bus lines with Ag ink, inkjet for the source/drain electrodes with glycerol-doped Poly (3,4-ethylenedioxythiophene): Poly (styrenesulfonate) (PEDOT:PSS), inkjet for the semiconductor layer with Triisopropylsilylethynyl (TIPS)-pentacene, and screen printing for the pixel electrodes with Ag paste. A mobility of $0.44cm^2/V$ s was obtained, with an average standard deviation of 20%, from the 36 OTFTs taken from different backplane locations, which indicates high uniformity. An EPD laminated on an OTFT backplane with $190{\times}152$ pixels on an 8-in panel was successfully operated by displaying some patterns.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1274-1274
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• 2008

In this report, the effect of substrate temperature on the electrical properties of ink-jet printed triisopropylsilyl (TIPS) pentacene organic thin-film transistors (OTFTs) has been investigated. The electrical properties such as mobility and on/off ratio were decreased as the substrate was heated above room temperature. The field-effect mobility of decreased from $10^{-2}cm^2/Vs$ to $10^{-5}cm^2/Vs$ and the on/off ratio decreased from $10^6$ to $10^4$ when the substrate temperature was heated from room temperature to 60$^{\circ}C$.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.637-637
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• 2013

We develop single-crystal poly(3,4-ethylenedioxythiopene nanowires using liquid-bridge-mediated nanotransfer printing via vapor phase polymerization. This direct printing method can simultaneously enable the synthesis, alignment and patterning of the nanowires from molecular ink solutions. Twoor three-dimensional complex structures of various single-crystal organic nanowires were directly fabricated over a large area using many types of molecular inks. This method is capable of generating several optoelectronic devices. LB-nTM is based on the direct transfer of various materials from a mold to a substrate via a liquid bridge between them. To demonstrate its usefulness, we used LB-nTM to fabricate nanowire field-effect transistors and arrays of 6,13-bis (triisopropyl- silylethynyl) pentacene (TIPS-PEN) nanowire field-effect transistors.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.264-264
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• 2008

We fabricated a pentacene thin-film transistor with a Polymer/$SiO_2$ Double Gate Dielectrics and obtained a device with better electrical characteristics. This device was found to have a field-effect mobility of $0.04cm^2$/Vs, a threshold voltage of -2V, an subthreshold slope of 1.3 V/decade, and an on/off current ratio of $10^7$.