• 한국전기전자재료학회논문지
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• 제26권2호
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• pp.87-91
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• 2013

Carbon-nanotube field-effect transistors (CNFETs) have drawn wide attention as one of the potential substitutes for metal-oxide-semiconductor field-effect transistors (MOSFETs) in the sub-10-nm era. Output characteristics of coaxially gated CNFETs were simulated using FETToy simulator to reveal the dependence of drain current on the nanotube diameter and gate oxide thickness. Nanotube diameter and gate oxide thickness employed in the simulation were 1.5, 3, and 6 nm. Simulation results show that drain current becomes large as the diameter of nanotube increases or insulator thickness decreases, and nanotube diameter affects the drain current more than the insulator thickness. An equation relating drain saturation current with nanotube diameter and insulator thickness is also proposed.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.78-78
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• 2013

This study has investigated the nanotube morphology control of Ti-30Nb-xTa alloys by applied voltages. The morphology changed from small diameter to large diameter with increasing applied voltage, whereas, changed from large diameter to small diameter with decreasing applied voltage.

• 센서학회지
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• 제27권4호
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• pp.264-268
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• 2018

Vertically-aligned $TiO_2$ nanotube electrodes have attracted considerable attention for applications in solar cells, catalysts, and sensors, because of their ideal structure for electron transport and electrolyte diffusion. Here, we prepare vertically-aligned $TiO_2$ nanotube electrodes using a two-step anodization process. The prepared $TiO_2$ nanotube electrodes exhibit uniform pore structures with an inner diameter of ~80-90 nm and wall thickness of ~20-25 nm. In addition, they exhibit an anatase crystal phase after a high-temperature annealing. The annealed $TiO_2$ nanotube electrodes are applied in dye-sensitized solar cells (DSSCs) as photoanodes. The fabricated DSSC exhibits conversion efficiencies of 3.46 and 2.15% with liquid- and gel-type electrolytes, respectively.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.559-562
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• 2004

Carbon nanotube is a geometrical frame-like structure and the primary bonds between two nearest-neighboring atoms act like beam members, whereas an individual atom acts as the joint of the related beam members. The sectional property parameters of these beam members are obtained from molecular mechanics. Computations of the elastic deformation of single-walled carbon nanotubes reveal that the Young's moduli of carbon nanotubes vary with the tube diameter and are affected by their helicity. With increasing tube diameter, the Young's moduli of carbon nanotubes approach the Young's modulus of graphite.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.893-896
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• 2012

Using molecular dynamics simulation method, we studied the carbon nanotube (CNT) non-covalently interacting with a polymer. As the polymer coiled around the CNT, the diameter of CNT deformed by more than 40% of its original value within 50 ps. By considering three different polymers, we conclude that the interaction between the CNT and polymer is governed by the number of repeating units in the polymer, not by the molecular weight of polymer.

• 한국전기전자재료학회논문지
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• 제33권1호
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• pp.45-49
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• 2020

In this paper, we prepared miniature fuse fabricated with carbon nanotube (CNT) fiber for the use of low rated current under 1 A and high speed operation under 4ms. CNT fuses were fabricated in the form of universal modular fuse (UMF) with different diameter of CNT fibers defined by multiplying the CNT threads. Electrical properties of the CNT fuses were measured such as resistance, rated current, and operation time with current. Resistance of the CNT fuse decreased and rated current increased with the diameter of the CNT fuses, respectively. Consequently, the operation time with current increased with the diameter of the CNT fuses. The CNT fuses fabricated in this work had broad range of low rated current from 0.05 to 1.25 A by multiplying the CNT threads. Operation time was measured about 3.6ms which was applicable to the UMF.

• 조명전기설비학회논문지
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• 제24권3호
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• pp.14-19
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• 2010

Partial anodic oxidation of Ti-mesh with a wire diameter of ~200[${\mu}m$] produces self-aligned $TiO_2$ nanotube arrays (~50[${\mu}m$] in length) on Ti-mesh substrate. The electrolyte used for anodic oxidation was an ethylene glycol solution with an addition of 1.5 vol. % $H_2O$ and 0.2 wt. % $NH_4F$. A dye-sensitized solar cell utilizing the photoanode structure of $TiO_2$-nanotube/Ti-mesh was fabricated without a transparent conducting oxide (TCO) layer, in which Ti-mesh replaced the role of TCO. The 1.93[%] photoconversion efficiency was low, which can be attributed to both insufficient dye molecules attachment and limited electrolyte flow to dye molecules. The optimized nanotube diameter and length as well as the $TiCl_4$ treatment can improve cell performance.

• Transactions on Electrical and Electronic Materials
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• 제11권3호
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• pp.112-115
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• 2010

This paper provides the properties of $TiO_2$ nanotube arrays which are fabricated by anodic oxidation of Ti metal. Highly ordered $TiO_2$ nanotube arrays could be obtained by anodic oxidation of Ti foil in $0.3\;wt{\cdot}%$ $NH_4F$ contained ethylene glycol solution at $30^{\circ}C$. The length, pore size, wall thickness, tube diameter etc. of $TiO_2$ nanotube arrays were analyzed by field emission scanning electron microscopy. Their crystal properties were studied by field emission transmission electron microscopy and X-ray photoelectron spectroscopy.

• 한국진공학회지
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• 제18권6호
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• pp.488-493
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• 2009

탄소나노튜브 Array를 고성능의 전자소자로 응용하고자 함에 있어, 탄소나노튜브의 전기적 특성을 결정짓는 길이와 직경을 제어하는 일은 매우 중요하다. 본 연구에서는 비교적 간단한 공정을 통하여 탄소나노튜브의 길이를 제어하는 기술을 개발 하였다. 기판에 평행하게 정렬된 탄소나노튜브 Array 박막을 열화학기상증착법을 이용하여 성장 시킨 후, 간단한 포토 리소그래피 공정과 산소 플라즈마 에칭 공정을 통하여 균일한 길이의 탄소나노튜브 Array를 기판위에 형성하였다. 본 연구를 통하여 개발된 균일한 길이의 고밀도 탄소나노튜브 Array는 대면적의 나노전자 소자뿐만 아니라, 태양전지, 바이오센서 등에 적용할 수 있다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2000년도 Proceedings of 5th International Joint Symposium on Microeletronics and Packaging
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• pp.109-109
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• 2000

Recently, carbon nanotube has been investigating for field emission display ( (FED) applications due to its high electron emission at relatively low electric field. However, the growing of carbon nanotube generally requires relatively high temperature processing such as arc-discharge (5,000 ~ $20,000^{\circ}C$) and laser evaporation (4,000 ~ $5,000^{\circ}C$) methods. In this presentation, low temperature growing of carbon nanotube by plasma enhanced chemical vapor deposition (PECVD) using nickel catalyst which is compatible to conventional FED processing temperature will be described. Carbon n notubes with average length of 100 run and diameter of 2 ~ $3\mu$ill were successfully grown on silicon substrate with native oxide layer at $550^{\circ}C$using nickel catalyst. The morphology and microstructure of carbon nanotube was highly depended on the processing temperature and nickel layer thickness. No significant carbon nanotube growing was observed with samples deposited on silicon substrates without native oxide layer. This is believed due to the formation of nickel-silicide and this deteriorated the catalytic role of nickel. The formation of nickel-silicide was confirmed by x-ray analysis. The role of native oxide layer and processing parameter dependence on microstructure of low temperature grown carbon nanotube, characterized by SEM, TEM XRD and R없nan spectroscopy, will be presented.