• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.417-417
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• 2009

Although a transparent conductive film (TCF) belongs to essential supporting materials for many device applications such as touch screens, flat panel displays, and sensors, a conventional transparent conductive material, indium-tin oxide (ITO), suffers from considerable drawback because the price of indium has soared since 2001. Despite a recent falloff, a demand of ITO is expected to increase sharply in the future due to the trend of flat panel display technologies toward flexible, paper-like features. There have been recently extensive studies to replace ITO with new materials, in particular, carbon nanotubes (CNTs) since CNTs possess excellent properties such as flexibility, electrical conductivity, optical transparency, mechanical strength, etc., which are prerequisite to TCFs. This study fabricated TCFs with single-walled carbon nanotubes (SWCNTs) produced by arc discharge. The SWCNTs were dispersed in water with a surfactant of sodium dodecyl benzene sulfonate (NaDDBS) under sonication. Carbon black and fullerene nanoparticles were added to the SWCNT-dispersed solution to enhance contact resistance between CNTs. TCFs were manufactured by a filtration and transfer method. TCFs added with carbon black and fullerene nanoparticles were characterized by scanning electron microscopy (SEM), UV-vis spectroscopy (optical transmittance), and four-point probe measurement (sheet resistance).

• Korean Journal of Materials Research
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• v.19 no.9
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• pp.488-493
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• 2009

Thin films of single-wall carbon nanotubes (SWNT) with various thicknesses were fabricated, and their optical and electrical properties were investigated. The SWNTs of various thicknesses were directly coated in the arc-discharge chamber during the synthesis and then thermally and chemically purified. The crystalline quality of the SWNTs was improved by the purification processes as determined by Raman spectroscopy measurements. The resistance of the film is the lowest for the chemically purified SWNTs. The resistance vs. thickness measurements reveal the percolation thickness of the SWNT film to be $\sim$50 nm. Optical absorption coefficient due to Beer-Lambert is estimated to be $7.1{\times}10^{-2}nm^{-1}$. The film thickness for 80% transparency is about 32 nm, and the sheet resistance is 242$\Omega$/sq. The authors also confirmed the relation between electrical conductance and optical conductance with very good reliability by measuring the resistance and transparency measurements.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.76-80
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• 2011

The ITO/Cabon Nano Tube (CNT) nano composites were deposited by nano cluster deposition (ITO) and arc discharge deposition (CNT) on glass substrates. The structural, optical and photovoltaic performance of ITO/CNT nano composites as a counter electrode of dye-sensitized solar-cells (DSSCs) such films were investigated. At low temperature below $250^{\circ}C$, the ITO films deposited on CNT. The ITO/CNT nano composit showed a good optical and electrical property for the counter electrode of DSSCs. When the as-prepared ITO/CNT nano composites are used for the counter electrodes, the photovoltaic parameters are $V_{OC}$ = 0.69 V, $J_{SC}$ = 5.69 mA/$cm^2$, FF = 0.32, and $\eta$ = 0.53 %. The ITO/CNT nano composites showed the possibility for the counter electrode applications of DSSCs.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1560-1563
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• 1987

This paper is concerned with time delay modeling of ED MOS gates which takes into account the slope of input waveform as well as the load condition. Defining the delay time as the time required to charge/discharge the load to the physical reference level, the rise/fall delay times arc derived in an explicit formula in terms of the sum of optimally weighted current unbalances at two end points of voltage transition. The proposed model is computationally effective and the error is typically within 10% of the SPICE results.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.1233-1234
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• 2006

A simple new method to fabricate transparent carbon nanotube field emission devices was developed. The highly graphitized single wall carbon nanotubes were attached on Sn/ITO glass by arc discharge method. Post heat treatments below the deformation temperature of soda-lime glass guaranteed a good mechanical adhesion and electrical contact of the nanotubes. The Sn layer was oxidized below $400^{\circ}C$ and became transparent. As increasing the oxidation temperatures, the emission properties became stable and life time of emitter has been increased.

• Carbon letters
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• v.14 no.3
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• pp.131-144
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• 2013

The carbon nanotube (CNT) represents one of the most unique inventions in the field of nanotechnology. CNTs have been studied closely over the last two decades by many researchers around the world due to their great potential in different fields. CNTs are rolled graphene with $SP^2$ hybridization. The important aspects of CNTs are their light weight, small size with a high aspect ratio, good tensile strength, and good conducting characteristics, which make them useful as fillers in different materials such as polymers, metallic surfaces and ceramics. CNTs also have potential applications in the field of nanotechnology, nanomedicine, transistors, actuators, sensors, membranes, and capacitors. There are various techniques which can be used for the synthesis of CNTs. These include the arc-discharge method, chemical vaporize deposition (CVD), the laser ablation method, and the sol gel method. CNTs can be single-walled, double-walled and multi-walled. CNTs have unique mechanical, electrical and optical properties, all of which have been extensively studied. The present review is focused on the synthesis, functionalization, properties and applications of CNTs. The toxic effect of CNTs is also presented in a summarized form.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1383-1384
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• 2007

직류 고전압을 사용한 글라이딩 아크 플라즈마 반응기에서 휘발성 유기 화합물(Volatile Organic Compounds, VOCs)의 일종인 기상의 벤젠 분해 연구가 진행되었다. 실험에는 압축공기와 벤젠(500ppm)으로 이루어진 혼합가스와 그 농도를 조절하기위한 압축공기가 사용되었다. 기본 방전 특성을 오실로스코프를 이용하여 분석하였다. 벤젠가스의 분해율은 글라이딩 아크 플라즈마와의 반응 전후의 가스를 포집하여 GC(Gas Chromatography)를 통해 정량 분석하여 비교하였다.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1484-1485
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• 2007

글라이딩 아크 플라즈마의 화학적 반응성을 이용하여 대표적 휘발성 유기 화합물인 벤젠의 분해를 위한 연구를 수행하였다. 실험에는 벤젠과 공기의 mixture gas를 사용하였다. 글라이딩 아크 플라즈마에 공급되는 전력을 변화시키며 각 regime의 방전 특성을 아크주의 방전 특성을 나타낸 O. Mayr의 식에 따라 살펴보았으며 플라즈마와의 반응전.후의 mixture gas내 포함되어 있는 벤젠 peak area의 크기를 GC(Gas Chromatography)를 통해 분석하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.9-15
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• 2004

The most shortcoming of metalhalide lamps is what the instant restarting cannot be realized when the arc tube is in the hot condition. The discharge starting voltage of arc tube in the hot condition is much higher than in the cold condition. Therefore it takes about five minutes to restart the metalhalide lamps, that is to say, it is possible to start when the pressure and the temperature are decreased. But, if the lamp is restarted in the hot condition, we must supply the high voltage pulse with 20[kV] at the both electrode of lamp. The proposed electronic ballast is consist of a electromagnetic interference(EMI) filter, a power factor correction(PFC) circuit, a flyback converter, a half-bridge inverter, and a high voltage igniter circuit. By this composition we can start/restart the lamp with the voltage 20[kV], even if the lamp is in the hot condition.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.8
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• pp.96-101
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• 2007

Gas Discharge Tubes (GDTs) are widely used as surge protectors for communication applications due to their small internal capacitance. In these days, however, they are mostly used in combined configurations, because the sparkover voltage required to initiate the discharge process in the GDTs and the time taken for arc formation process can be large enough to damage to sensitive circuits. For GDTs with a considerably high initial residual voltage, we should limit the peak voltage using a TVS or filter. We made a hybrid SPD circuits of common-mode type and differential-mode type with the filter using common-mode choke. Also, we applied lightning impulse voltage and ring wave voltage which frequency bandwidth are different each other and verified the characteristics of hybrid SPD circuits according to waveshapes. We describe how the applied SPDs operate in protection process steps with the actual data obtained from the residual voltage measurement at each step. The experiment results show that the surge voltage reduction with the choke coil is more effective in differential-mode circuit than in common-mode circuit.