• 한국재료학회지
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• 제21권4호
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• pp.207-211
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• 2011

Ni 8 wt.%-doped tin oxide ($SnO_2$) thick films were fabricated into gas sensors by the method of screen printing onto alumina substrates. The particle size of $SnO_2$ was controlled by changing the ball-mill time between 0~120 h. The structural and morphological properties of these thick films were investigated using X-ray diffraction and scanning electron microscopy. The structural properties of $SnO_2$ powders showed a tetragonal phase with (110) dominant orientation. The particle size of the $SnO_2$:Ni powders after ball-mill of 120 h was about 0.05 ${\mu}m$. The gas sensitivity (S = Rg/Ra) to 5 ppm $CH_4$ gas and $CH_3CH_2CH_3$ gas was measured at room temperature by comparing the resistance in air (Ra) with that of the target gases (Rg). The sensitivity of the $SnO_2$ gas sensors was enhanced by increasing the ball-mill time. There was an association between the sensitivity of both the $CH_4$ gas and the $CH_3CH_2CH_3$ gas and the particle size of the $SnO_2$. $SnO_2$ gas sensors prepared by 72 h ball-mill showed a sensitivity of about 13 to 5 ppm $CH_4$ gas and $CH_3CH_2CH_3$ gas. The response time of the $SnO_2$:Ni gas sensors to the $CH_4$ gas was about 20 seconds.

• 한국세라믹학회지
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• 제40권10호
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• pp.973-980
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• 2003

n-type 반도체인 SnO$_2$ 가스센서에서 첨가제가 산화성 가스에 대한 감지특성에 미치는 영향을 살펴보았다 SnO$_2$ 센서는 환원성 가스에 노출될 경우 전자 주게로 작용하여 저항이 감소하지만, 반대로 산화성 가스에 노출될 경우 전자 받게로 작용하여 저항이 증가하는 특성을 보인다 산화성 가스와 SnO$_2$ 분말 사이의 반응생성물을 가스 크로마토그래피 분석을 통하여 환원성 가스인 알콜의 반응 생성물과 비교하였다. PdC1$_2$혹은 A1$_2$O$_3$가 첨가된 센서는 산화성의 $CH_3$CN와 $CH_3$NO$_2$에 대해 동작온도에 따라 독특한 이중반응특성을 보였다. 이들 센서들의 조합과 패턴인식 기법을 이용하면 전자수용기를 가진 가스들에 대한 선택성을 높일 수 있을 것이다.

• 한국표면공학회지
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• 제44권4호
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• pp.144-148
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• 2011

$Ga_2O_3$ doped $SnO_2$ thin films were grown by using pulsed laser deposition (PLD) technique on glass substrate. The optical and electrical properties of these films were investigated for different doping concentrations, oxygen partial pressures, substrate temperatures, and film thickness. The films were deposited at different substrate temperatures (room temperature to $600^{\circ}C$). The best opto-electrical properties is shown by the film deposited at substrate temperature of $300^{\circ}C$ with oxygen partial pressure of 80 m Torr and the gallium concentration of 2 wt%. The as obtained lowest resistivity is $9.57{\times}10^{-3}\;{\Omega}cm$ with the average transmission of 80% in the visible region and an optical band gap (indirect allowed) of 4.26 eV.

• 센서학회지
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• 제17권4호
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• pp.295-302
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• 2008

$TiO_2,\;ZrO_2$, and $SiO_2$ were added in the concentration of 1 - 3 wt.% to improve long-term stability for the $SnO2$ thick film gas sensor. Short-term sensor resistances up to 90 h were measured to investigate the stabilization time of initial resistance in air. Long-term resistance drifts in air and in gas to 5000 ppm methane for the sensors annealed at $750^{\circ}C$ for 1 h and continuously heated at an operating temperature of $400^{\circ}C$ were also measured up to 90 days at an interval of 1 day. The long-term drifts in methane sensitivity for the three metal oxide-doped $SnO2$ sensors are closely related to methane sensitivity level, catalytic activity, and long-term drift in sensor resistance in air. Those stabilities are mainly discussed in terms of oxidation state and catalytic activity.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.110.1-110.1
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• 2012

Recently, advances in ZnO based oxide semiconductor materials have accelerated the development of thin-film transistors (TFTs), which are the building blocks for active matrix flat-panel displays including liquid crystal displays (LCD) and organic light-emitting diodes (OLED). However, the electrical performances of oxide semiconductors are significantly affected by interactions with the ambient atmosphere. Jeong et al. reported that the channel of the IGZO-TFT is very sensitive to water vapor adsorption. Thus, water vapor passivation layers are necessary for long-term current stability in the operation of the oxide-based TFTs. In the present work, $Al_2O_3$ and $TiO_2$ thin films were deposited on poly ether sulfon (PES) and $SnO_x$-based TFTs by electron cyclotron resonance atomic layer deposition (ECR-ALD). And enhancing the WVTR (water vapor transmission rate) characteristics, barrier layer structure was modified to $Al_2O_3/TiO_2$ layered structure. For example, $Al_2O_3$, $TiO_2$ single layer, $Al_2O_3/TiO_2$ double layer and $Al_2O_3/TiO_2/Al_2O_3/TiO_2$ multilayer were studied for enhancement of water vapor barrier properties. After thin film water vapor barrier deposited on PES substrate and $SnO_x$-based TFT, thin film permeation characteristics were three orders of magnitude smaller than that without water vapor barrier layer of PES substrate, stability of $SnO_x$-based TFT devices were significantly improved. Therefore, the results indicate that $Al_2O_3/TiO_2$ water vapor barrier layers are highly proper for use as a passivation layer in $SnO_x$-based TFT devices.

• 센서학회지
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• 제6권4호
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• pp.274-279
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• 1997

$WO_{3}$ 모물질로 하여 NOx 검지센서를 제조하여 전기적 특성과 가스감지특성을 알아 보았다. $SnO_{2}$와 $TiO_{2}$를 포함한 $WO_{3}$ 후막은 동작온도 $400^{\circ}C$에서 순수한 $WO_{3}$ 후막보다 NOx가스에 대한 뛰어난 감도와 가스 흡탈착 특성을 보였다. $TiO_{2}-WO_{3}$ 후막에 Ru와 Au와 같은 귀금속 촉매를 특별히 첨가하여 제작된 센서에서는 NOx 가스에 대한 감도, 회복 속도 및 선택도 등을 더욱 개선되었다.

• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2005년도 제36차 춘계학술대회 및 제3회 HVEM 이용자 워크샵
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• pp.59-65
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• 2005

• 한국세라믹학회지
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• 제38권1호
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• pp.100-105
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• 2001

An all solid-state thin film battery (TFB) was fabricated by growing, undoped and Pt-doped vanadium oxide cathode film ( $V_2$ $O_{5}$ ) on I $n_2$ $O_3$: Sn coated glass, respectively. Room temperature charge-discharge measurements based on Li/Lipon/ $V_2$ $O_{5}$ full-cell structure with a constant current clearly shows that the Pt-doped $V_2$ $O_{5}$ cathode film is superior, in terms of cyclibility. X-ray diffraction (XRD) results indicate that the Pt doping process induces a more random amorphous structure than an undoped $V_2$ $O_{5}$ film. In addition to its modified structure, the Pt-doped $V_2$ $O_{5}$ film has a smoother surface than the undoped sample. Compared to an undoped $V_2$ $O_{5}$ film, the Pt doped $V_2$ $O_{5}$ cathode film has a higher electron conductivity. We hypothesize that the addition of Pt alters electrochemical performance in a manner of making more random amorphous structure and gives an excess electron by replacing the $V^{+5}$. Possible mechanisms are discussed for the observed Pt doping effect on structural and electrochemical properties of vanadium oxide cathode films, which are grown on I $n_2$ $O_3$: Sn coated glass.

• 한국표면공학회지
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• 제29권5호
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• pp.519-524
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• 1996

We synthesized semiconducting Sn-doped diamondlike carbon films by rf plasma-enhanced chemical vapor deposition using an organotin compound as a dopung gas source. XPS quan-titative analysis for the deposited films after 60 s argon ion etching revealed that Sn concen-tration increased with the partial pressure of the organotin compound in the reactant gas. In C 1s spectra, there was a component due to C-Su bond which had a negative chemical shift. C 1s spectra also indicated that the deposited films were relatively $sp^2$ rich. The chemical shift of the Sn-C bond in Sn $3d_{5/2}$ spectra was about +1.7 eV. The electrical resistivity and the optical transmittance were also investigated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.57.2-57.2
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• 2010

투명전도 산화막(Transparent conducing oxide: TCO)은 태양 전지, 터치패널, 가스 센서 등 여러 분야에 적용할 수 있는 물질로서 전기 전도성과 광 투과성을 동시에 가진다. 높은 전기 전도성과 광 투과성을 가지는 Sb:$In_2O_3$(ITO)는 투명전도 산화막 재료로써 가장 일반적으로 사용되고 있으나 인듐의 매장량 한계로 인해 가격이 높다는 단점이 있다. 본 연구에서는 ITO 대체 TCO 물질인 Al doped ZnO(AZO)를 rf magnetron sputter를 이용하여 최적의 수소 도핑량을 찾아 ITO의 전기적 광학적 성질과 비교하였다. AZO 박막은(ZnO:Al2O3 2wt.%)타겟을 이용하여 heater 온도 250도에서 슬라이드 글래스 및 코닝 글래스에 증착시켰고 비교군인 ITO박막은 (In2O3:$SnO_2$ 10wt.%)타겟을 이용하여 수소 도핑 없이 350도로 증착시켰다. AZO 및 ITO 박막의 전기적 특성은 hall measurement를 이용하여 측정하였고, UV-VIS spectrophotometer로 광학적 특성을 측정하였다. 수소 도핑량이 증가함에 따라 AZO 박막의 캐리어 농도가 증가하여 전기적 특성이 향상되었고, 가시광 영역에서 높은 평균 투과도를 유지 하였다. AZO 박막과 ITO 박막의 전기적 및 광학적 특성을 비교한 결과, 최적 수소 도핑량을 가진 AZO 박막은 ITO 박막에 준하는 특성을 보였다.