• 제목/요약/키워드: Nanowire arrays

검색결과 73건 처리시간 0.032초

High Density Silver Nanowire Arrays using Self-ordered Anodic Aluminum Oxide(AAO) Membrane

  • Kim, Yong-Hyun;Han, Young-Hwan;Lee, Hyung-Jik;Lee, Hyung-Bock
    • 한국세라믹학회지
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    • 제45권4호
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    • pp.191-195
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    • 2008
  • Highly ordered silver nanowire with a diameter of 10 nm was arrayed by electroless deposition in a porous anodic aluminum oxide(AAO) membrane. The AAO membrane was fabricated electrochemically in an oxalic acid solution via a two-step anodization process, while growth of the silver nanowire was initiated by using electroless deposition at the long-range-ordered nanochannels of the AAO membrane followed by thermal reduction of a silver nitrate aqueous solution by increasing the temperature up to $350^{\circ}C$ for an hour. An additional electro-chemical procedure was applied after the two-step anodization to control the pore size and channel density of AAO, which enabled us to fabricate highly-ordered silver nanowire on a large scale. Electroless deposition of silver nitrate aqueous solution into the AAO membrane and thermal reduction of silver nanowires was performed by increasing the temperature up to $350^{\circ}C$ for 1 h. The morphologies of silver nanowires arrayed in the AAO membrane were investigated using SEM. The chemical composition and crystalline structure were confirmed by XRD and EDX. The electroless-deposited silver nanowires in AAO revealed a well-crystallized self-ordered array with a width of 10 nm.

태양전지용 $Cu_2S$ 나노와이어의 제작 및 특성분석 (Copper Sulfide Nanowires for Solar Cells)

  • 임영석;강윤묵;김원목;김동환
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 춘계학술대회
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    • pp.166-169
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    • 2006
  • We fabricated hexagonal copper sulfide $Cu_2S$ nanowires to obtain a larger contact area of $Cu_2S/CdS$ solar cell. Copper sulfide nanowires were grown on Cu foil at room temperature by gas-sol id reaction. The size, density and shape of nanowires seemed to be affected by the change or reaction time temperature, crystallographic orientation of Cu foil, and molar ratio of the mixed gas. We controled the length and the diameter of the nanowires and we obtained suitable nanowire arrays which has fitting size for uniform deposition with n-type CdS. CdS layer was deposited on the nanowire array by electrodeposition and it seemed to be uniform. The $Cu_2S/CdS$ nanowires/CdS junction showed diode characteristics, A large contact area is expected with the $Cu_2S/CdS$ nanowire structure as compared with the $Cu_2S/CdS$ thin film.

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III-V족 화합물 반도체 InSb 나노와이어의 전기화학적 합성 및 특성 평가 (Electrochemical Formation and Characterization of III-V Compound Semiconductor InSb Nanowires)

  • 이관희;이종욱;박호동;정원용;이종엽
    • 전기화학회지
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    • 제8권3호
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    • pp.130-134
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    • 2005
  • 본 연구에서는 그동안 전기화학적으로 합성되지 못했던 III-V족 화합물 반도체 InSb를 구연산 용액으로부터 합성하였으며 자체 제조한 AAO를 나노템플릿으로 이용하여 정전압 도금을 실시하여 InSb 나노와이어를 제조하였다 제조된 InSb나노와이어는 X선 회절분석 결과 단결정의 나노와이어는 아니었으나 정확하게 화학양론을 만족시키는 화합물임을 확인하였고, 평판 박막 상태의 InSb와는 달리 나노와이어의 길이방향으로 (220) 방향의 결정이 주로 성장하는 우선결정방위를 가지고 있음을 알 수 있었다. 또한 집합적으로 배열된 상태에서 측정된 I-V특성 곡선에서는 n형 반도체의 특성을 보이되 밴드갭이 좁고, 전자이동도가 큰 InSb고유의 특성상 반금속과 유사한 전기적 특성을 보유하고 있음을 확인하였다.

Temperature dependence of the effective anisotropy in Ni nanowire arrays

  • Meneses, Fernando;Urreta, Silvia E.;Escrig, Juan;Bercoff, Paula G.
    • Current Applied Physics
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    • 제18권11호
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    • pp.1240-1247
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    • 2018
  • Magnetic hysteresis in Ni nanowire arrays grown by electrodeposition inside the pores of anodic alumina templates is studied as a function of temperature in the range between 5 K and 300 K. Nanowires with different diameters, aspect ratios, inter-wire distance in the array and surface condition (smooth and rough) are synthesized. These microstructure parameters are linked to the different free magnetic energy contributions determining coercivity and the controlling magnetization reversal mechanisms. Coercivity increases with temperature in arrays of nanowires with rough surfaces and small diameters -33 nm and 65 nm- when measured without removing the alumina template and/or the Al substrate. For thicker wires -200 nm in diameter and relatively smooth surfaces- measured without the Al substrate, coercivity decreases as temperature rises. These temperature dependences of magnetic hysteresis are described in terms of an effective magnetic anisotropy $K_a$, resulting from the interplay of magnetocrystalline, magnetoelastic and shape anisotropies, together with the magnetostatic interaction energy density between nanowires in the array. The experimentally determined coercive fields are compared with results of micromagnetic calculations, performed considering the magnetization reversal mode acting in each studied array and microstructure parameters. A method is proposed to roughly estimate the value of $K_a$ experimentally, from the hysteresis loops measured at different temperatures. These measured values are in agreement with theoretical calculations. The observed temperature dependence of coercivity does not arise from an intrinsic property of pure Ni but from the nanowires surface roughness and the way the array is measured, with or without the alumina template and/or the aluminum support.

Nanowire Patterning for Biomedical Applications

  • Yun, Young-Sik;Lee, Jun-Young;Yeo, Jong-Souk
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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    • pp.382-382
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    • 2012
  • Nanostructures have a larger surface/volume ratio as well as unique mechanical, physical, chemical properties compared to existing bulk materials. Materials for biomedical implants require a good biocompatibility to provide a rapid recovery following surgical procedure and a stabilization of the region where the implants have been inserted. The biocompatibility is evaluated by the degree of the interaction between the implant materials and the cells around the implants. Recent researches on this topic focus on utilizing the characteristics of the nanostructures to improve the biocompatibility. Several studies suggest that the degree of the interaction is varied by the relative size of the nanostructures and cells, and the morphology of the surface of the implant [1, 2]. In this paper, we fabricate the nanowires on the Ti substrate for better biocompatible implants and other biomedical applications such as artificial internal organ, tissue engineered biomaterials, or implantable nano-medical devices. Nanowires are fabricated with two methods: first, nanowire arrays are patterned on the surface using e-beam lithography. Then, the nanowires are further defined with deep reactive ion etching (RIE). The other method is self-assembly based on vapor-liquid-solid (VLS) mechanism using Sn as metal-catalyst. Sn nanoparticle solutions are used in various concentrations to fabricate the nanowires with different pitches. Fabricated nanowries are characterized using scanning electron microscopy (SEM), x-ray diffraction (XRD), and high resolution transmission electron microscopy (TEM). Tthe biocompatibility of the nanowires will further be investigated.

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Direct printing of organic single crystal nanowire arrays by using Liquid-bridge-mediated nanotransfer molding

  • Oh, Hyun-S.;Baek, Jang-Mi;Sung, Myung-M.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.473-473
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    • 2011
  • In recent years, organic thin film transistors OTFTs based on conductive-conjugated molecules have received significant attention. We report a fabrication of organic single crystal nanowires that made on Si substrates by liquid bridge-mediated nanotransfer molding (LB-nTM) with polyurethane acrylate (PUA) mold. LB-nTM is based on the direct transfer of various materials from a stamp to a substrate via a liquid bridge between them. In liquid bridge-transfer process, the liquid layer serves as an adhesion layer to provide good conformal contact and form covalent bonding between the organic single crystal nanowire and the Si substrate. Pentacene is the most promising organic semiconductors. However pentacene has insolubility in organic solvents so pentacene OTFTs can be achieved with vacuum evaporation system. However 6, 13-bis (triisopropylsilylethynyl) (TIPS) pentacene has high solubility in organic solvent that reported by Anthony et al. Furthermore, the substituted rings in TIPS-pentacene interrupt the herringbone packing, which leads to cofacial ${\pi}-{\pi}$ stacking. The patterned TIPS-Pentacene single crystal nanowires have been investigated by Atomic force microscopy (AFM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and electrical properties.

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Lateral p-n junction Diode with organic single crystal by direct printing

  • Park, Yoon kyoung;Sung, Myung Mo
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.144.1-144.1
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    • 2016
  • We fabricate organic single crystal nanowire heterojunction p-n diode poly(3-hexylthiophene)(P3HT) and from Phenyl-C61-butyric acid methyl ester(PCBM) using by liquid-bridge mediated nanotransfer molding(LB-nTM) method. LB-nTM has been reported an one step direct printing method for making well-aligned nanowire arrays. Moreover, multi-patterning nanostructures can be fabricated with the consecutive printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as lateral organic p-n nanojunction diode. P3HT/PCBM nanowires heterojunction diode has rectifying behavior with on/off ratios of ~20.

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Fabrication of 6, 13-bis(triisopropylsilylethynyl) (TIPS) pentacene -Nanowire Arrays Using Nano Transfer Molding

  • Oh, Hyun-S.;Sung, Myung-M.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2010년도 제39회 하계학술대회 초록집
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    • pp.284-284
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    • 2010
  • We report a fabrication of 6, 13-bis(triisopropylsilylethynyl) (TIPS) pentacene nanowires that made on Si substrates by liquid bridge-nanotransfer molding (LB-nTM) with polyurethane acrylate (PUA) mold. LB-nTM is based on the direct transfer of various materials from a stamp to a substrate via a liquid bridge between them. In liquid bridge-transfer process, the liquid layer serves as an adhesion layer to provide good conformal contact and form covalent bonding between the TIPS-pentacene nanowire and the Si substrate. The patterned TIPS-Pentacene nanowires have been investigated by Atomic force microscopy (AFM), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and electrical properties.

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Single-Crystal Organic Semiconductor Nanowires as Building Blocks for Nanojunction Devices

  • 이기석;이린;성명모
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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    • pp.261.1-261.1
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    • 2013
  • Well-aligned nanowire arrays can be used as building blocks for nanoscale device. Recently, we reported that well-aligned single-crystal organic nanowires has been created by using a direct printing method which is named liquid-bridge mediated nanotransfer molding (LB-nTM). Moreover, multi-layering nanostructures can be fabricated by repeating this printing process. As a result, it is possible to make simple and basic concept of heterojunction devices such as crossed nanowire devices. We fabricated crossed single-crystal organic nanowires nanojunction devices from 6,13-bis (triisopropylsilylethynyl) pentacene (TIPS-PEN) and fullerene (C60) single-crystal nanowires using by direct printing method in solution process. Crossed TIPSPEN/ C60 single-crystal nanowires diode has rectifying behavior with on/off ratios of ~13. In addition, the device shows photodiode characteristics as well as rectification. Our study represent methodology of heterojunction devices using single-crystal nanowires, thereby provide a new direction of future nanoelectronics.

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