• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.70-73
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• 2004

Two different $SnO_2$ nanomaterials(nanowires and nanobelts) were synthesized from the thermal evaporation of ball-milled $SnO_2$ powders at $1350^{\circ}C$ without the presence of any catalysts, and their structural properties are then investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. This investigation reveals that the $SnO_2$ nanowires are single-crystalline and their growth direction is parallel to the [100] direction, and that the $SnO_2$ nanobelts are single crystalline and their shape is zigzag. In addition, photoresponse of a single $SnO_2$ nanowire was performed with light above-gap energy, and different characteristics of photoresponse were obtained for the nanowire at ambient atmosphere and in vacuum.

• 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.160-161
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• 2008

$SnO_2$는 n형 반도체로써 3.6 eV의 큰 밴드갭을 가지는 물질로 CO와 NOx 가스에 좋은 감도를 나타내는 것으로 보고되고 있다. 문헌에 따른 일반적인 $SnO_2$ 가스센서는 후막이나 벌크형태로 제작되었다. 근래에는 가스감응체가 $SnO_2$ 나노선 형태인 가스센서가 활발한 연구 중에 있다. 본 논문에서는 기판 위에 서로 분리된 전극 패턴에 Au를 촉매로 하여 네트워크 구조로 된 $SnO_2$ 나노선이 합성되었다. 제작된 가스센서에 Pd 도핑에 따른 영향을 알아보기 위하여 1.8 mM의 Pd 용액 ($PdCl_2{\cdot}xH_2O$ 3 mg + $H_2O$ 10 ml)을 이용하여 센서에 도핑하였다. 측정 시스템에서 $NO_2$ 가스에 대한 센서의 특성을 분석한 결과 도핑하지 않은 $SnO_2$ 센서보다 20%정도의 감도가 개선되었다.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2013년도 춘계학술대회 논문집
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• pp.165-165
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• 2013

브랜치 구조의 나노섬유는 기존의 1-d 나노 구조보다 표면적이 넓으며 이로 인해 가스 센서 특성 향상에 응용 할 수 있다. $SnO_2$ stem nanowire구조에 ZnO branch를 성장시킴으로서 효과적인 가스 센싱을 위한 나노 브랜치 구조의 합성을 하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.273-273
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• 2010

Recently, extensive research on hetero-junction arrays has been reported owing to its unique band gaps dissimilar to that of homo-junctions. These hetero-junction devices can be used in laser, solar cells, and various sensors. We report on the facile method to fabricate SWCNTs/SnO2 nanowires hetero-junction arrays on flexible polyimide substrate. Each SWCNT field effect transistor (FET) and SnO2 nanowire FET exhibits the purely p- and n-type charactersistics with ohmic contact properties. Such formed pn-junctions showed rectification behaviors reproducibly with a rectification ratio of ${\sim}3{\times}103$ at 1 V and ideality factors about 12. The pn-junctions also showed a good gate modulation behavior.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2009년도 추계학술대회 초록집
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• pp.186-187
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• 2009

단일 나노선 적용 센서의 단점을 극복하고 신뢰성이 높은 센서를 구현하고자 vapor-liquid-solid (VLS) 법을 이용하여 $SnO_2$ 나노선의 선택적 성장을 통한 나노선 네트워크 구조의 센서를 제조하였다. 분리된 전극층의 변화에 따른 나노선의 접합 특성 변화에 이에 따른 나노선 네트워크 센서의 가스감지 특성을 고찰하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.132.2-132.2
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• 2010

Mesoporous tinoxide ($SnO_2$) as anode materials for Li-ion battery were prepared by hydrothermal method and templating method using SBA-15 as template. And electrochemical properties of $SnO_2$ electrode were investigated with cyclic voltammogram (CV). The morphology and structures of $SnO_2$ were characterized by transmission electron microscopy (TEM) and X-ray diffractometer (XRD), respectively. The specific surface area was defined by $N_2$ adsorption with BET(Brunauer-Emmett-Teller) method. As a result, the surface area of mesoporous $SnO_2$ which was made from templating method is higher than the case of using hydrothermal method. In addition, in anodic performance, mesoporous $SnO_2$ which is prepared by templating method showed higher charge-discharge capasity compared to hydrothermal method and exhibited excellent stability over the entire cycle number. It was indicated that electrochemical performances of mesoporous $SnO_2$mainly affected to the structural features, such as specific surface area and porosity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.430.1-430.1
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• 2014

According to advanced nanotechnology in the field of biomedical engineering, many studies of the interaction between topography of surfaces and cellular responses have been focused on nanostructure. In order to investigate this interaction, it is essential to make well-controlled nanostructures. Electron beam lithography (EBL) have been considered the most typical processes to fabricate and control nano-scale patterns. In this work, $TiO_2$ nanowire array was fabricated with hybrid process (top-down and bottom-up processes). Nanodot arrays were patterned on the substrate by EBL process (top-down). In order to control the spacing between nanodots, we optimized the EBL process using Poly(methyl methacrylate) (PMMA) as an electron beam resist. Metal lift-off was used to transfer the spacing-controlled nanodots as a seed pattern of $TiO_2$ nanowire array. Au or Sn nanodots which play an important role for catalyst using Vapor-Liquid-Solid (VLS) method were patterned on the substrate through the lift-off process. Then, the sample was placed in the tube furnace and heated at the synthesis temperature. After heat treatment, $TiO_2$ nanowire array was fabricated from the nanodots through VLS method (bottom-up). These results of spacing-controlled nanowire arrays will be used to study the interaction between nanostructures and cellular responses in our next steps.

• 센서학회지
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• 제20권5호
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• pp.289-293
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• 2011

Networked $SnO_2$ nanowires were uniformly functionalized with Pd nanoparticles via ${\gamma}$-ray radiolysis. The Networked $SnO_2$ nanowires were fabricated through a selective growth method. The sensing properties of the Pd-functionalized $SnO_2$ nanowires were analyzed in terms of their response to $NO_2$ and CO gases. The response time and sensitivity of the sensors were significantly improved for $NO_2$ at lower temperatures by the Pd functionalization. The enhancement in the sensing properties is likely to be due to the spillover effect of the Pd nanoparticles.

• 한국재료학회지
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• 제25권3호
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• pp.125-131
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• 2015

Fluorine-doped $SnO_2$ (FTO) thin film/Ag nanowire (NW) double layers were fabricated by means of spin coating and ultrasonic spray pyrolysis. To investigate the optimum thickness of the FTO thin films when used as protection layer for Ag NWs, the deposition time of the ultrasonic spray pyrolysis process was varied at 0, 1, 3, 5, or 10 min. The structural, chemical, morphological, electrical, and optical properties of the double layers were examined using X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, the Hall effect measurement system, and UV-Vis spectrophotometry. Although pure Ag NWs formed isolated droplet-shaped Ag particles at an annealing temperature of $300^{\circ}C$, Ag NWs covered by FTO thin films maintained their high-aspect-ratio morphology. As the deposition time of the FTO thin films increased, the electrical and optical properties of the double layers degraded gradually. Therefore, the double layer fabricated with FTO thin films deposited for 1 min exhibited superb sheet resistance (${\sim}14.9{\Omega}/{\Box}$), high optical transmittance (~88.6 %), the best FOM (${\sim}19.9{\times}10^{-3}{\Omega}^{-1}$), and excellent thermal stability at an annealing temperature of $300^{\circ}C$ owing to the good morphology maintenance of the Ag NWs covered by FTO thin films.