• 센서학회지
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• 제30권3호
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• pp.175-180
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• 2021

In this paper, methods for improving the sensitivity of gas sensors to NO₂ gas are presented. A gas sensor was fabricated based on an SnO₂ nanowire network using the vapor-phase-growth method. In the gas sensor, the Au electrode was replaced with a fluorinedoped tin oxide (FTO) electrode, to achieve high sensitivity at low temperatures and concentrations. The gas sensor with the FTO electrode was more sensitive to NO₂ gas than the sensor with the Au electrode: notably, both sensors were based on typical SnO₂ nanowire network. When the Au electrode was replaced by the FTO electrode, the sensitivity improved, as the contact resistance decreased and the surface-to-volume ratio increased. The morphological features of the fabricated gas sensor were characterized in detail via field-emission scanning electron microscopy and X-ray diffraction analysis.

• 한국표면공학회지
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• 제50권6호
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• pp.455-459
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• 2017

The development of flexible transparent electrode has been paid attention for flexible electronics. In this study, we have developed transparent electrode based on silver nanowires with improved electrical property and stability through ion-beam treatment. The energetic particles of ion-beam could sinter junctions of each silver nanowires and etch out polyvinylpyrollidone(PVP) coated on silver nanowires. The sheet resistance of silver nanowire transparent electrode was reduced by 74%, and the resistance uniformity was increased about 3 times after exposure of ion beam. Moreover, the stability at $85^{\circ}C$ of temperature and 85% of relative humidity could be also improved.

• 대한전자공학회논문지SD
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• 제45권4호
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• pp.49-56
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• 2008

본 논문은 효율적인 회로 시뮬레이션을 위한 긴 채널 공핍 모드 n형 나노선 전계효과트랜지스터(nanowire field-effect transistor: NWFET)의 간단한 해석적 전류 전도 모델을 소개한다. 본 연구에서 사용된 NWFET는 bottom-up 방식으로 제작되었으며 게이트가 채널의 아래에 존재하는 구조를 가진다. 이 모델은 다양한 바이어스 조건에서 동작하는 NWFET의 모든 전류 전도 메카니즘을 포함한다. 새롭게 개발된 NWFET 모델로 계산된 결과는 이전에 발표된 NWFET 실험 데이터와 비교할 때 10% 오차범위 안에서 서로 일치한다.

• 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.

• 마이크로전자및패키징학회지
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• 제22권1호
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• pp.7-14
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• 2015

Recently, advances in nano-material researches have opened the door for various transparent conductive materials, which include carbon nanotube, graphene, Ag and Cu nanowire, and printable metal grids. Among them, Ag nanowires are particularly interesting to synthesize because bulk Ag exhibits the highest electrical conductivity among all metals. Here we reviewed recently-published research works introducing various devices from organic light emitting diode to tactile sensing devices, all of which are employing AgNW for a conducting material. They proposed methods to enhance the stretchability and reversibility of the transparent electrodes, and apply them to make various flexible and stretchable electronics. It is expected that Ag nanowires are applicable to a wide range of high-performance, low-cost, stretchable electronic devices.

• 한국전기전자재료학회논문지
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• 제23권11호
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• pp.848-853
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• 2010

We have grown GaN nanowires by the low pressure MOCVD method on Ni deposited oxidized Si surface and have established optimum conditions by observing surface microstructure and its photoluminescence. Optimum growth temperature of $880^{\circ}C$, growth time of 30 min, TMG source flow rate of 10 sccm have resulted in dense nanowires on the surface, however further increase of growth time or TMG flow rate has not increased the length of nanowire but has formed nanocrystals. On the contrary, the increase of ammonia flow has increased the length of nanowires and the coverage of nanowire over the surface. The shape of nanowire is needle-like with a Ni droplet at its tip; the length is tens of micron with more than 40 nm in diameter. Low temperature photoluminescence obtained from the sample at optimum growth condition has revealed several peaks related to exciton decay near band-edge, but does not show any characteristic originated from one dimensional quantum confinement. Strong and broad luminescence at 2.2 eV is observed from dense nanowire samples and this suggests that the broad band is related to e-h recombination at the surface state in a nanowire. The current result is implemented to the nanowire device fabrication by nanowire bridging between micro-patterned neighboring Ni catalysis islands.

• JSTS:Journal of Semiconductor Technology and Science
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• 제11권2호
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• pp.80-87
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• 2011

Low temperature hole transport characteristics of gate-all-around p-channel metal oxide semiconductor (PMOS) type silicon nanowire field-effect-transistors with the radius of 5 nm and lengths of 44-46 nm are presented. They show coexisting two single hole states randomly switching between each other. Analysis of Coulomb diamonds of these two switching states reveals a variety of electrostatic effects which is originated by the potential of a single hole captured in the trap near the nanowire.

• 대한전자공학회논문지SD
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• 제47권9호
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• pp.24-29
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• 2010

본 논문에서는 30 nm 채널 길이와 5 nm의 채널 반지름을 갖는 실리콘 기반의 나노와이어 MOSFET의 고주파 모델링을 다루고 있다. 3차원 소자 시뮬레이션을 이용하여 실리콘 나노와이어 MOSFET의 Y-parameter와 Z-parameter를 100 GHz까지 확보하였으며 이를 이용하여 모델 파라미터에 필요한 수식을 구하였다. 모델과 파라미터 추출 수식을 이용하여 회로 검증용 tool인 HSPICE에 의하여 검증이 이루어졌으며 quasi-static 기반의 고주파 모델이 100 GHz의 높은 주파수까지도 소자의 특성을 정확히 예측함을 확인하였다. 모델 검증은 MOSFET의 포화 영역 ($V_{gs}$ = $_{ds}$ = 1 V)과 선형 영역 ($V_{gs}$ = 1 V, $V_{ds}$ = 0.5 V)의 바이어스 조건에서 이루어졌으며 두 바이어스 조건에서의 Y-parameter에 대한 모델의 오차는 약 1 %로 매우 작은 값을 보여 준다.

• 전기전자학회논문지
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• 제10권2호통권19호
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• pp.161-167
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• 2006

본 연구는 단일 ZnO 나노선의 광전 특성에 대한 에이징(aging) 효과에 관한 것이다. 합성 직후의 ZnO 나노선에 대하여 photoluminescence (PL), 광전류 스펙트럼, 전류-전압 특성 및 광응답 특성들을 측정하였고, ZnO 나노선을 3달 동안 공기 중에 노출시킨 후에 위의 실험을 반복하였다. 에이징된 나노선은 합성 직후의 나노선과 비교하여 넓은 영역의 PL 밴드는 약해졌고, 광전류의 크기는 증가하였으며, 광응답 속도는 느려졌다. 본 연구에서 PL를 통해 관찰된 에이징 효과는 나노선 내부에 산소 공극의 수가 감소함으로 인한 것이며, 광전류와 광응답 특성에서 에이징 효과는 나노선 표면 부근에 산소 공극의 형성으로 인한 것이다.

• 전자공학회논문지
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• 제53권3호
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• pp.39-45
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• 2016

본 논문에서는 게르마늄 응축 공정을 모델링하고 공정을 적용한 나노와이어 구조의 게르마늄 PMOSFET의 특성을 소자 시뮬레이션을 통하여 확인하였다. 기존의 연구 결과들을 토대로 하여 모델링을 수행한 결과, 게르마늄 응축 공정 과정에서 얻게 되는 벌크 영역에서의 게르마늄 농도($C_B$)에 대한 실리콘 게르마늄-실리콘 산화막 계면에서의 게르마늄 농도의 비율($C_S$)은 약 4.03, 해당 공정 온도에서 게르마늄 원자의 유효 확산 계수($D_{eff}$)은 약 $3.16nm^2/s$으로 추출되었다. 나아가, 게르마늄 응축 공정을 통하여 구현할 수 있는 실리콘 코어 상에 얇은 게르마늄 채널을 갖는 나노와이어 채널 구조의 PMOSFET을 설계하고 성능을 분석하였다. 이를 통하여, 전영역을 실리콘으로 혹은 게르마늄으로 하는 채널을 갖는 소자에 비하여 실리콘 코어-게르마늄 채널의 동축 이종접합 채널을 갖는 소자가 우수한 특성을 가질 수 있음을 확인하였다.