• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.481-482
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• 2006

We fabricated pentacene organic thin film transistor with good uniformity. And we extracted contact resistance in organic thin film transistors from the plot of the inverse of drain current versus channel length by extrapolating the curve to a channel length of zero, and multiplying by drain-source voltage. Extracted contact resistance is about $70K{\Omega}$ at gate-drain voltage of -20 V

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.271-272
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• 2008

We fabricated a pentacene thin-film transistor with Ni/Ag source/drain electrodes. Also, we obtained similar electrical characteristics as compared with source/drain electrode with Au. This device was found to have a field-effect mobility of about 0.021 $cm^2$/Vs, a threshold voltage of -5, -7 V, an subthreshold slope of 2.0, 4.5 V/decade, and an on!off current ratio of $3.6\times10^5$, $2.0\times10^6$.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1115-1118
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• 2006

Using a thermally-crosslinkable organosiloxane-based organic-inorganic hybrid material, solution processable gate dielectric layer for organic thin-film transistors (OTFTs) have been fabricated. The hybrid dielectrics are synthesized by the sol-gel process, followed by the heat-treatment at $190{\bullet}\;.{\bullet}$ To investigate the electrical property of hybrid dielectric, leakage current behavior and capacitance were measured. To fabricate coplanar-type OTFTs, Au/Cr electrode was deposited onto the heavily doped silicon substrate with the organic-inorganic hybrid dielectric layer and then ${\alpha},{\omega}-dihexylquaterthiophene$ was drop-cast between source and drain electrical performance of the fabricated transistor.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.194-197
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• 2002

Applying dual layer insulator on plastic substrates improved electrical characteristics of organic thin film transistor(TFT). A high-quality silicon dioxide(SiO$_2$) suitable for a insulator was deposited on plastic substrates by e-beam evaporation at 110$^{\circ}C$. The insulator film which was treated by N$_2$ annealing at 150$^{\circ}C$ showed excellent I-V, C-V characteristics. The dual layer insulator structure of polyimide-SiO$_2$ improved the roughness of SiO$_2$ surface and showed very low leakage current. In addition, the flat band voltage has been reduced from -2.5V to about 0.5V.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.8
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• pp.7-12
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• 2010

In this paper, $C_{60}$ based Organic thin film transistor OTFTs) have been fabricated using BPhen(Bathophenanthroline) and BPhen doped with Cs interlayers between $C_{60}$ active layer and Al electrodes to improve the electrical performance. The addition of the BPhen layer resulted in enhanced performances by reducing surface roughness between organic-metal interface. And the contact resistance was reduced by using the BPhen doped with Cs interlayer with co-evaporation method. These performances suggests that the $C_{60}$ based OTFT with BPhen doped with Cs interlayer is a promising application in the fabrication of n-type organic transistors.

• Korean Journal of Metals and Materials
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• v.60 no.3
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• pp.198-205
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• 2022

In this study, we demonstrate high-performance optical wavelength-selective organic thin-film transistors (TFTs) that incorporate heterogeneous organic semiconductor materials, poly(3-hexylthiophene) (P3HT) and 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene). The electrical characteristics of the fabricated transistors were analyzed in the dark to determine how the P3HT:TIPS-pentacene ratio of the semiconductor affected the performance of the transistor. Specifically, the P3HT:TIPS-pentacene weight ratio was varied (1:0, 1:0.25, 1:0.5, 1:0.75, 1:1, and 0:1) by blending 1 wt% P3HT dissolved in chloroform, and 1 wt% TIPS-pentacene dissolved in anisole. The UV-visible light absorbance characteristics of the films containing the P3HT, TIPS-pentacene, and P3HT:TIPS-pentacene blends were analyzed. Monochromatic light at wavelengths of 515 and 450 nm was used to clarify the influence of irradiation on the electrical characteristics of the TFTs. The results confirmed that the TFT containing P3HT:TIPS-pentacene at a blending ratio of 1:0.5 had the largest light-to-dark current ratio, i.e., approximately 33.8 and 23.5 when exposed to monochromatic light at wavelengths of 515 nm and 450 nm, respectively. The TFT with the P3HT:TIPS-pentacene blending ratio of 1:0.5 exhibited the highest photosensitivity values of 261.9 and 49.6 upon irradiation with light at wavelengths of 515 nm and 450 nm, respectively. The observed improvement in the performance of the heterogeneously blended organic transistors is discussed in relation to the morphological structure and charge transport path of the P3HT:TIPS-pentacene blended semiconductor films.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.543-545
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• 2009

With injection-type source delivery system of atomic layer deposition (ALD), bottom-contact and bottom-gate thin-film transistors (TFTs) were fabricated with a poly-4-vinyphenol polymeric dielectric for the first time. The properties of the ZnO TFT were greatly influenced by the device structure and the process conditions. The zinc oxide TFTs exhibited a channel mobility of 0.43 $cm^2$/Vs, a threshold voltage of 0.85 V, a subthreshold slope of 3.30 V/dec, and an on-to-off current ratio of above $10^6$ with solid saturation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.7
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• pp.531-536
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• 2012

We herein present results of flat and uniform polymer-blended small molecular semiconductor thin films. Which were produced for organic thin film transistors (OTFTs), using a simple pre-metered horizontal dipping process. The organic semiconducting thin films were composed of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-PEN) composite blended with a polymer binder of poly(${\alpha}$-methylstyrene) (PaMS). We show that the pre-metered horizontal-dip-coating(H-dip-coating) process allowed the critical control of the thickness of the blended TIPS-PEN:PaMs thin film. The fabricated OTFTs using the TIPS-PEN:PaMs films exhibited maximum field-effect mobility of $0.22\;cm^2\;V^{-1}\;s^{-1}$. These results demonstrated that H-dip-coated TIPS-PEN:PaMS films show considerable promise for the production of reliable, reproducible, and high-performance OTFTs.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.777-779
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• 2002

We report the performance of pentacene-based organic thin film transistors (OTFT) with PMMA (polymethyl methacrylate) as the gate insulator which was spin-coated on the ITO (indium tin oxide) glass substrate which was used as the gate contact. The pentacene thin film was deposited on the PMMA film and then Au source/drain contacts were deposited through shadow mask. The pentacene film shows better molecular ordering on PMMA compared with $SiO_2$ of Si wafer. The devices exhibited the field effect mobility of ${\sim}0.004cm^2$/Vs and on/off current ratio of ${\sim}10^3$.

• Journal of the Korean Applied Science and Technology
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• v.19 no.4
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• pp.335-338
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• 2002

A new process for polymeric gate insulator in field-effect transistors was proposed. Fourier transform infrared absorption spectra were measured in order to identify ODPA-ODA polyimide. Its breakdown field and electrical conductivity were measured. All-organic thin-film transistors with a stacked-inverted top-contact structure were fabricated to demonstrate that thermally evaporated polyimide films could be used as a gate insulator. As a result, the transistor performances with evaporated polyimide was similar with spin-coated polyimide. It seems that the mass-productive in-situ solution-free processes for all-organic thin-film transistors are possible by using the proposed method without vacuum breaking.