• 한국전기전자재료학회논문지
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• 제25권5호
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• pp.349-352
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• 2012

ZnO thin films were deposited on a-, c- and m- plane oriented 4H-SiC substrates by pulsed laser deposition. ZnO nanowires were formed on substrates by tube furnace. Shape and density of the ZnO nanowires were investigated by field emission scanning electron microscope. Average surface roughness and root mean square surface roughness were measure by atomic force microscope. Optical properties were investigated by Photoluminescence measurement. Density of ZnO nanowires grown on a-, c- and m-plane oriented 4H-SiC substrates were 17.89 ${\mu}m^{-2}$, 9.98 ${\mu}m^{-2}$ and 2.61 ${\mu}m^{-2}$, respectively.

• 한국생산제조학회지
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• 제21권6호
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• pp.855-859
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• 2012

Silicon nanowires (SiNWs) were fabricated by a metal-assisted chemical etching of Si and the porous structure on their surfaces was controlled by changing the volume ratio of the etching solution composed of hydrofluoric acid, hydrogen peroxide, and deionized water. The concentration of hydrogen peroxide as the oxidant was varied for controlling the porosity of SiNWs. The optical properties of porous SiNWs were unique and very different from those of single-crystalline Si, as characterized by measuring their photoluminescence and Raman spectra for different porosities.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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• pp.81-83
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• 2005

Photocurrent of a single-crystalline Si nanowire is investigated in this paper. Single-crystalline Si nanowires with amorphous $SiO_2$ shells were first synthesized from ball-milled SiO powders by thermal chemical vapor deposition, and then the amorphous $SiO_2$ shellswere etched out from the as-synthesized Si nanowires. For a single-crystalline Si nanowire, photocurrent-voltage curves taken in air at room temperature were non-linear, and rapid photoresponses were observed when the light was switched on and off. The photocurrent was not changed in intensity under the illumination. Photocurrent mechanism in the single-crystalline Si nanowire is discussed in this paper.

• 융합정보논문지
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• 제7권5호
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• pp.123-128
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• 2017

나노구조를 갖는 물질들은 나노구조물이 갖는 고유의 체적 대비 높은 표면적 비와 양자 갇힘 효과에 기인하는 독특한 전기적, 광학적, 광전기적, 자기적 특성으로 인하여 많은 주목을 받아왔다. 열화학 기상 증착 공정은 나노 구조물의 성장과정에서 다양한 구조를 갖는 나노소재의 합성 능력 때문에 더욱 주목을 받아왔다. 본 연구에서는 두 영역 열화학 기상 증착법과 소스 물질 $TiO_2$ 파우더를 이용하여 VLS 공정으로 Si\$SiO_2$(300 nm)\Pt(5~40 nm) 기판 위에 실리콘 옥사이드 나노와이어를 성장시켰다. 성장된 실리콘 옥사이드 나노와이어의 형상과 결정학적 특성을 전계방출 주사전자현미경과 투과전자현미경으로 분석하였다. 분석결과, 성장된 실리콘 옥사이드 나노와이어의 형상인 지름과 길이는 촉매 박막의 두께에 의존하여 다른 모양을 나타내었다. 또한 성장된 실리콘 옥사이드 나노와이어는 비정질 상을 갖는 것으로 분석되었다.

• 한국재료학회지
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• 제13권10호
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• pp.677-682
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• 2003

SiC nanowires were synthesized by carbothermal reduction using metal catalysts. Synthesized nanowires had mean diameters of 30∼50 nm and several $\mu\textrm{m}$ length. The kind of catalysts affects form of SiC nanowire because of difference of growth mechanisms. These differences were made by catalyst's physical property and relative activities to the source gas. Ni acted a conventional catalyst of VLS growth mechanism. But, Case of Fe, SiC nanowire was grown by stable VLS growth mechanism without relation of growth conditions. SiC nanowire was grown by two step growth model using Cr catalyst. Conversion ratios to the SiC nanowire were increased with growth conditions. Case of Cr, conversion ratio was about 45% that was higher than other catalyst used. This high conversion ratio was obtained by the addition VS growth to radial direction on the as-grown nanowires.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 추계학술대회 논문집 Vol.17
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• pp.252-255
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• 2004

Various Semiconductor/Metal structured nanowires were synthesized from the simple thermal annealing of ball-milled compound powders and the thermal evaporation of metals. Their structural properties were investigated by Scanning Electron Microscopy(SEM) and Transmission Electron Microscopy(TEM), Energy Dispersive X-ray spectroscopy(EDX). Depending on the type of metals and the material of nanowires, uniform somiconductor/metal nanowires(GaN/Al, GaN/Ag) or isolated metal particles on semiconductor nanowires$(SnO_2/Ti,\;Si/Ti)$ were formed on the surface of nanowires.

• 한국전기전자재료학회논문지
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• 제25권11호
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• pp.922-925
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• 2012

Single crystalline Au nanowires were successfully synthesized in a tube-type furnace. The Au nanowires were grown by vapor phase synthesis technique using solid-liquid-solid (SLS) mechanism on substrates of corning glass and Si wafer. Prior to Au nanowire synthesis, Au thin film served as both catalyst and source for Au nanowire was prepared by sputtering process. Average length of the grown Au nanowires was approximately 1 ${\mu}m$ on both the corning glass and Si wafer substrates, while the diameter and the density of which were dependent on the thickness of the Au thin film. To induce a super-saturated states for the Au particle catalyst and Au molecules during the Au nanowire synthesis, thickness of the Au catalyst thin film was fixed to 10 nm or 20 nm. Additionally, synthesis of the Au nanowires was carried out without introducing carrier gas in the tube furnace, and synthesis temperature was varied to investigate the temperature effect on the resulting Au nanowire characteristics.

• 통합자연과학논문집
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• 제10권2호
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• pp.65-73
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• 2017

In this review paper, we will discuss about the methods of synthesizing Si nanowires by Top-down and Bottom-up. Silicon nanowires have a lot of application on various fields such as Li ion batteries, solar cells, chemical and biological sensors. We will address some of the applications of silicon Nanowires.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2010년도 임시총회 및 하계학술연구발표회
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• pp.79-79
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• 2010

Semimetallic bismuth (Bi) has been extensively investigated over the last decade since it exhibits very intriguing transport properties due to their highly anisotropic Fermi surface, low carrier concentration, long carrier mean free path l, and small effective carrier mass $m^*$. In particular, the great interest in Bi nanowires lies in the development of nanowire fabrication methods and the opportunity for exploring novel low-dimensional phenomena as well as practical application such as thermoelectricity[1]. In this work, we introduce a self-assembled interconnection of nanostructures produced by an on-film formation of nanowires (OFF-ON) method in order to form a highly ohmic Bi nanobridge. A Bi thin film was first deposited on a thermally oxidized Si (100) substrate at a rate of $40\;{\AA}/s$ by radio frequency (RF) sputtering at 300 K. The sputter system was kept in an ultra high vacuum (UHV) of $10^{-6}$ Torr before deposition, and sputtering was performed under an Ar gas pressure of 2m Torr for 180s. For the lateral growth of Bi nanowires, we sputtered a thin Cr (or $SiO_2$) layer on top of the Bi film. The Bi thin films were subsequently put into a custom-made vacuum furnace for thermal annealing to grow Bi nanowires by the OFF-ON method. After thermal annealing, the Bi nanowires cannot be pushed out from the topside of the Bi films due to the Cr (or $SiO_2$) layer. Instead, Bi nanowires grow laterally as a mean s of releasing the compressive stress. We fabricated a self-assembled Bi nanobridge (d=192 nm) device in-situ using OFF-ON through annealing at $250^{\circ}C$ for 10hours. From I-V measurements taken on the Bi nanobridge device, contacts to the nanobridge were found highly ohmic. The quality of the Bi nanobridge was also proved by the high MR of 123% obtained from transverse MR measurements. These results manifest the possibility of self-assembled nanowire interconnection between various nanostructures for a variety of applications and provide a simple device fabrication method to investigate transport properties on nanowires without complex patterning and etching processes.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2007년도 춘계학술발표대회 및 제12회 신소재 심포지엄
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• pp.4.1-4.1
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• 2007