• 제목/요약/키워드: Nanotube structure

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CNT-BLU Local Dimming 구동을 이용한 LCD Contrast 향상 방법 (LCD contrast ratio enhancement method using Carbon Nanotube Back Light Unit and Local Dimming)

  • 민경원;정득석;송병권;김선일;강호석;백찬욱;정태원;김정우;진용완;조준동
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2006년도 하계종합학술대회
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    • pp.971-972
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    • 2006
  • We have demonstrated Carbon Nanotube Back Light Unit (CNT-BLU) which has a triode structure. Local dimming scheme was introduced to the BLU driving system. With this driving method, contrast ratio enhanced 20 times higher than that of conventional Cold Cathode Fluorescent Lamp (CCFL) BLU.

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다중스케일 기법을 이용한 카본나노튜브 복합재료의 물성치 계산 (Estimation of material properties of carbon nanotube composite applying multi-scale method)

  • 김정택;현석정;김철
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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    • pp.165-168
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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.

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Carbon Nanotube Passivation layer for Increasing the Solar Water Splitting Performance of CdS/CuInGaSe Photocathode

  • Bae, Hyojung;Ko, Young-Hee;Park, Jun-Beom;Ko, Hang-Ju;Ryu, Sang-Wan;Ha, Jun-Seok
    • 마이크로전자및패키징학회지
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    • 제26권4호
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    • pp.107-111
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    • 2019
  • We report the fabrication of a CdS/CuInGaSe (CdS/CIGS) structure with carbon nanotubes and its application as a photocathode for photoelectrochemical water splitting. CIGS thin films were fabricated using co-evaporation by RF magnetron sputtering, while CdS was fabricated by chemical bath deposition. Spray coated multi-wall carbon nanotube (CNT) film on CdS/CIGS thin film was investigated as a photocathode. The CNT-coated CdS/CIGS showed superior photocurrent density and exhibited improved photostability.

The Electronic Structure of Carbon Nanotubes with Finite Length : Tight Binding Theory

  • Moon, Won-Ha;Kim, Won-Woo;Hwang, Ho-Jung
    • Transactions on Electrical and Electronic Materials
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    • 제3권1호
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    • pp.23-29
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    • 2002
  • The electronic properties of Carbon Nanotube(CNT) are currently the focus of considerable interest. In this paper, the electronic properties of finite length effect in CNT for the carbon nano-scale device is presented. To Calculate the electronic properties of CNT, Empirical potential method (the extended Brenner potential for C-Si-H) for carbon and Tight Binding molecular dynamic (TBMD) simulation are used. As a result of study, we have known that the value of the band gap decreases with increasing the length of the tube. The energy band gap of (6,6) armchair CNT have the ranges between 0.3 eV and 2.5 eV. Also, our results are in agreements with the result of the other computational techniques.

Nanotube Morphology Change of Ti-Ta-Zr Alloy as Zr Content

  • Kim, Won-Gi;Choe, Han-Cheol;Ko, Yeong-Mu
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2008년도 추계학술대회 초록집
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    • pp.105-106
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    • 2008
  • Nanotube morphology change of Ti-Ta-Zr alloy as Zr content increase has been researched using various experimental methods. Ti-Ta-Zr(3, 7 and 15 wt%) alloys were prepared by arc melting and nano-structure controlled for 24 hr at $1000^{\circ}C$ in argon atmosphere. Formation of oxide nanotubes are conducted by anodizing a Ti-Ta-Zr alloy in $H_3PO_4$ electrolytes with small amounts of fluoride ions at room temperature. Electrochemical experiments were carried out with conventional three-electrode configuration with a platinum counter electrode and a saturated calomel reference electrode. The samples were embedded with epoxy resin, leaving a square surface area of $10mm^2$ exposed to the anodizing electrolyte, 1.0M $H_3PO_4$ containing 0.8wt% NaF.

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Carbon Nanotube Gate-Elongated Tunneling Field Transistor(CNT G-E TFET) to Reduce Off-Current

  • 허재;전승배
    • EDISON SW 활용 경진대회 논문집
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    • 제2회(2013년)
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    • pp.240-242
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    • 2013
  • In this paper, novel Carbon Nanotube Gate-Elongated Tunneling Field Transistor(CNT G-E TFET) is proposed. This proposed device is designed to decrease off-current around 2~6 orders of magnitude compared to the gate-channel size matched TFET. Mechanism of CNT G-E TFET creates additional steps in energy band structure so that off-current can be reduced. Since CNT TFETs show a great probability for tunneling processes and they are beneficial for the overall device performance in terms of switching speed and power consumption, CNT G-E TFET looks pretty much promising.

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Field Emission of Carbon Nanotubes

  • Ihm, Jisoon;Han, Seungwu
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 하계학술대회 논문집
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    • pp.1-4
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    • 2000
  • We have performed ab initio pseudopotential electronic structure calculations for various edge geometries of the (n,n) singlewall nanotube with or without applied fields. Among the systems studied, the one with the zigzag edge exposed by a slant cut is found to be the most favorable for the emission due to the existence of unpaired dangling bond states around the Fermi level. The next favorable geometry is the capped nanotube where $\pi$-bonding states localized at the cap and pointing to the tube axis direction occur at the Fermi level. A scaling rule of the induced field linear in the aspect ratio of the tube is also obtained.

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Computational continuum modelling to analysis the dynamic and static stability of a cantilever nano-scale system

  • Jiangjiang Li
    • Advances in Computational Design
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    • 제8권1호
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    • pp.77-96
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    • 2023
  • Calculating size-dependent mechanical properties of the nano-scale materials usually involves cumbersome numerical and theoretical works. In this paper, we aim to present a closed-form relation to calculate the length-dependent Young's modulus of carbon nanotubes (CNTs) based on nonlocal elasticity theory. In this regard, a single wall carbon nanotube (SWCNT) is considered as a rod structure and the governing nonlocal equations are developed under uniaxial tensile load. The equations are solved using analytical methods and strain distribution, total displacement and the size-dependent equivalent Young's modulus are obtained. Further, the results are compared with the molecular dynamics results from the literature. The outcome indicates that the calculated relations are coincident with the molecular dynamics results.

탄소나노튜브 코팅의 마찰/마모 특성에 대한 나노메쉬 구조의 영향 (Effect of Nanomesh Structure Variation on the Friction and Wear Characteristics of Carbon Nanotube Coatings)

  • 김해진;김창래
    • Tribology and Lubricants
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    • 제36권6호
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    • pp.315-319
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    • 2020
  • In various fields, several studies based on carbon nanotubes (CNTs) have been conducted. The results of previous studies, wherein CNT coatings have been incorporated as solid lubricants, demonstrate that the friction and wear characteristics of CNT coatings can be improved through the absorption/dispersion of the contact pressure by controlling the stiffness of the nanomesh structure comprising CNT strands. In this study, the friction and wear characteristics of the following are compared: CNT coating formed by spin coating of CNT solution, compressed CNT coating, and compressed/heated CNT coating (wherein CNT strands are squeezed through compression and/or heating). It is observed that the friction coefficient of the CNT coating having the largest number of voids between the CNT strands is significantly lower than those of the compressed CNT coating and the compressed/heated CNT coating. The wear tracks of the compressed CNT coating and the compressed/heated CNT coating indicate that some parts become torn or adhere into a lump. However, in the case of the CNT coating, a smooth wear surface is formed by rubbing. Furthermore, as the void space between the squeezed and adhered CNT strands decreases, the resistance to structural deformation increases, thereby resulting in an increased frictional force and a wear pattern that becomes torn or forms a lump. Hence, the results obtained from this study corroborate that the friction and wear characteristics of CNT coatings can be enhanced through the absorption/dispersion of the contact pressure by controlling the stiffness of the nanomesh structure of CNT coatings.

Modeling of truncated nanocompositeconical shell structures for dynamic stability response

  • S.M.R. Allahyari;M. Shokravi;T.T. Murmy
    • Structural Engineering and Mechanics
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    • 제91권3호
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    • pp.325-334
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    • 2024
  • This paper deals with the dynamic buckling behavior of truncated conical shells composed of carbon nanotube composites, an important area of study in view of their very wide engineering applications in aerospace industries. In this regard, the effective material properties of the nanocomposite have been computed using the Mori-Tanaka model, which has already been established for such analyses. The motion equations ruling the structure's behavior are derived using first order shear deformation theory, Hamilton's principle, and energy method. This will provide adequate background information on its dynamic response. In an effort to probe the dynamic instability region of the structure, differential quadrature method combined with Bolotin's method will be adopted to tackle the resulting motion equations, which enables efficient and accurate analysis. This work considers the effect of various parameters in the geometrical parameters and the volume fraction of CNTs on the structure's DIR. Specifically, it became clear that increasing the volume fraction of CNTs shifted the frequency range of the DIR to higher values, indicating the significant role of nanocomposite composition regarding structure stability.