• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.225-231
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• 2006

.고상반응법 (solid state reaction)합성된 ZnS:Mn,Cu,Cl 형광체는 약 $20^{\sim}25{\mu}m$ 의 구형이고, Cubic/hexagonal 구조를 보였다. Electroluminescent device(ELD)는 실크 스크린된 형광층(ZnS:Mn,Cu,Cl)/유전체층 ($BaTiO_3$)으로 구성되었으며, 각층은 $30^{\sim}50{\mu}m,\;50^{\sim}60{\mu}m$ 정도로 도포 하였다. 100 V-400 Hz 의 구동조건에서, ELD 의 백색 발광은 450 nm, 480 nm 픽에서 각각 $Cl_s{\to}Cu^{+}\;_{Zn},\;Cl_s{\to}Cu^{2+}\;_{Zn}$ 전이에 의해 중첩된 청색, 녹색 밴드의 발광과, 580 nm 픽에서 Mn 의 $^{4}T_1{\to}^{6}A_1$ 전이에 의한 황색 밴드의 발광으로 이루어진다. Cu 농도의 증가에 따라 450 nm 의 발광 밴드의 휘도는 감소하며 580 nm 의 발광 밴드의 휘도가 증가하였고 발광 휘도가 향상되었다. 즉, 색온도가 높은 cold white(10000 K)에서 색온도가 낮은 Warm white(3000 K) 로 변한다. 이것은 450 nm 의 발광 밴드가 580 nm 의 발광 밴드에 흡수되는 에너지 전이 (Energy transfer) 현상에 기인한다. ZnS:Mn,Cu,Cl 의 Mn 1.5 wt %, Cu 2.5 wt.% 에서 최적 발광 휘도를 보이며, 100 V-400 Hz 에서 약 $12cd/cm^2$이였다.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.8 s.350
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• pp.13-18
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• 2006

[ $SnO_2$ ] and ZnO nanostructures were grown on the surface of thin film by heat treatment of metal Sn, Zn under Ar gas flow and $O_2$ at atmospheric pressure, respectively. The sensitivity of the $SnO_2$ thin film device on which grown nanowires to CO gas(5,000 ppm) was 50 % at the operating temperature of $200^{\circ}C$. In case of using Pt as catalysts, the sensitivity was enhanced and operating temperature was reduced(73 % at $150^{\circ}C$ ). The sensitivity of the ZnO nanorods device using Cu as catalysts to NOx gas was 90 % at the operating temperature of $200^{\circ}C$. It was found that the sensitivity to CO and NOx gases for the device on which grown nanostructures was much higher than those for general thin film device.

• Korean Journal of Plant Resources
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• v.12 no.3
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• pp.234-239
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• 1999

The isoenzyme patterns and activities of superoxide dismutase(SOD) were investigated from leaves of Araliaceae plants. Of the eight isoenzymes, two isoenzymes(SOD 4 and SOD 6) were prevalent to leaves of Araliaceae plants. The patterns of these two isoenzymes were most various in the leaves of Acanthopanax senticosus for. inermis, while their activity was highest in the leaves of A. koreanum. These two isoenzymes were respectively identified as Fe-SOD and CuZn-SOD, based on selective inhibition with KCN or$H_2O_2$. The SOD isoenzyme patterns did not differed among stem barks, root barks and leaves of A. koreanum. However, the activities of Fe-SOD and CuZn-SOD were higher in the root bark and in leaves, respectively. Both of Fe-SOD and CuZn-SOD were stable for 1 hr at 30-4$0^{\circ}C$, while unstable above 5$0^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.399.1-399.1
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• 2016

p-type 반도체 물질로 알려진 $Cu_2O$에 Li 이온을 doping하면 Cu 이온 자리에 Li이온이 치환되어 p-type의 특성이 더욱 강하게 나타내는 것으로 알려져 있다. 이에 본 연구에서는 RF magnetron sputtering방법으로 성막한 p-type형 $Li:Cu_2O$박막의 특성을 연구하고 이를 $Li:Cu_2O-ZnO$ pn 접합 유연 나노제너레이터에 적용하였다. $Li:Cu_2O$ 성막시 $O_2$ 분압을 변수로 100nm 두께의 $Li:Cu_2O$ 박막을 성막하여 전기적, 광학적, 구조적, 표면 특성을 분석하였다. Hall measurement 측정 결과 $Li:Cu_2O$ 박막은 정공을 Major Carrier로 갖는 p-type 반도체임을 확인하였고, $O_2$의 분압이 증가할수록 Mobility 및 Carrier Concentration이 증가함을 확인하였다. 최적조건에서 광학적 투과도는 약 45%를 보였으며, 투과도를 통해 계산한 band gap은 약 2.03eV로써 일반적인 산화물 반도체의 작은 밴드갭을 가지고 있음을 알 수 있었다. 또한 Ellipsometer분석을 통해 $Ar:O_2$ 비가 $Li:Cu_2O$ 굴절률 및 흡광도에 미치는 영향을 연구하였으며, FE-SEM(Field Emission Scanning Electron Microscope)을 통해 표면을 분석하였다. 또한 XRD(X-ray diffractometer), TEM(Transmission Electron Microscope) 분석을 통하여 상온에서 성막한 $Li:Cu_2O$ 박막의 미세구조를 연구하였다. UPS(Ultraviolet Photoelectron Spectroscopy) 분석을 통해 일함수를 측정하였다. 이렇게 제작된 p 타입 $Li:Cu_2O$ 박막을 이용하여 $Li:Cu_2O-ZnO$ pn 접합을 구현하고 이를 이용해 유연 나노제너레이터를 제작하였다. 다양한 특성 분석을 통해p-type을 이용한 산화물 박막 기반 유연 나노 제너레이터 특성 향상 메커니즘을 제시하였다.

• Journal of the Korean Ceramic Society
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• v.56 no.4
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• pp.354-359
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• 2019

Information security films that can ensure personal privacy by reducing the viewing angle of display screens were fabricated by microlouver patterning and a ZnO nano-ink filling process. Optical simulation results demonstrated that all the microlouver films showed good security performances. Security performances were evaluated as calculated relative luminance ratios compared between the side and front. Based on the simulation results, microlouver films were fabricated by UV imprint lithography and nano-ink bar coating. However, distortion of the microlouver pattern occurred with the use of high-viscosity nano-inks such as ZrO₂ and TiO₂, and the CuO-filled microlouver film suffered from very low optical transmittance. Accordingly, the effects of ZnO filling height on security performance were intensively investigated through simulation and experimental measurements. The fabricated microlouver film with a 75-㎛-high ZnO filling exhibited a good relative luminance ratio of 0.75 at a 60° side angle and a transmittance of 44% at a wavelength of 550 nm.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.390.1-390.1
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• 2016

The present work explains the interfacial energetics of all oxide transparent photodiodes. The optical, structural and morphological of copper oxides were systematically analyse by UV-Visible spectrometer, X-Ray diffraction, Raman spectroscopy, Scanning electron microscopy (SEM) and Atomic force microscopy measurements (AFM). The UV-Visible result exhibits optical bandgap of Cu2O and CuO as 2.2 and 2.05 eV respectively. SEM and AFM result shows a uniform grain size distribution in Cu2O and CuO thin films with the average grain size of 45 and 40 nm respectively. The results of Current-Voltage and Kelvin probe force microscope characteristics describe the electrical responses of the Cu2O/ZnO and CuO/ZnO heterojunctions photodiodes. The obtained electrical response depicts the approximately same knee voltages with a measurable difference in the absolute value of net terminal current. More over the present study realizes the all oxide transparent photodiode with zero bias photocurrent. The presented results lay the template for fabricating and analysing the self-bias all oxide transparent photodetector.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.327-327
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• 1999

The oxidation behavior of 60%Cu-40%Zn brass haying small amounts of Zr, Cr, Mg, Al, and Si was studied between 873 and 1043 K in air. The alloying element of Mg was harmful, while other alloying elements were beneficial to oxidation resistance. Particularly, the simultaneous addition of Al and Si decreased the oxidation rate drastically. During oxidation, Zr formed ZrO₂, Cr formed CuCr₂O₄, Mg formed MgO, Al formed A1₂CuO₄, and Si formed amorphous SiO₂. These oxides were incorporated in the oxide scale composed predominantly of ZnO. The oxide scales formed on all the tested alloyswere prone to cracking, wrinkling, and spallation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.291-291
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• 2009

ZnS:Mn/Cu,Cl 계 나노 형광체의 특성을 살펴보았다. 실험에서는 ZnS:Mn 과 ZnS:Cu,Cl 형광체 파우더를 이용하여 밀링을 통하여 분쇄하여 EL 소자를 제작하였다. 형광체 파우더를 볼밀에 $\Phi5mm$의 지르코나이 볼과 에탄올과 함께 넣고 2, 4, 6, 8, 10일간 밀링을 하였다. 밀링한 형광체 파우더를 SEM을 통하여 파우더의 사이즈를 관찰하였다. 또 이 파우더를 이용하여 EL 소자를 제작하였다. 소자의 구조는 기판은 알루미나 기판을, 하부 전극은 Au, 유전체는 $BaTiO_3$ 유전체 페이스트를 사용하였으며, 형광체 적층 후 ITO 전극을 스퍼터를 이용하여 증착하여 제작하였다. 제작한 소자를 이용하여 소자의 휘도 등 발광 특성을 살펴보았다.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.138-142
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• 1990

The effects of heavy metals Cd, Cu, Cr, Ni, and Zn on the degradation of the insecticide fenitrothion (O, O-dimethyl O-4-nitro-m-tolyl phosphorothioate), the fungicide IBP (5-benzyl O, O-diisopropyl phosphorothioate), and the herbicide butachlor (N-butoxymetyl-2-chloro-2', 6'-diethylacetanilide) in flooded soils were examined in the laboratory. The degradation of the 3 pesticides in soil was greatly inhibited by the amendment of the 5 heavy metals. The inhibition rate was high in the order of butachlor>IBP>fenitrothion. Populations of fenitrothion-and butachlor-degrading microbes, which were counted by the MPN method, were lower in heavy metals added soil than in the control soil. The effect of heavy metals on the degradation of the 3 pesticides in soil varied with the kind and concentration of heavy metals and the kind of pesticides.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.566-572
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• 2007

Two hybrid catalysts for the direct synthesis of DME were prepared and the catalytic activity of these catalysts were investigated. The hybrid catalyst for the direct synthesis of DME was composed as the catalytic active components of methanol synthesis and dehydration. The methanol synthesis catalyst was formed from the precursor contained Cu and Zn, the methanol dehydration catalyst was used ${\gamma}-Al_2O_3$. As PM-CZ+D and CP-CZA/D, Two hybrid catalysts were prepared by physical mixing method (PM-CZ+D) and precipitation method (CP-CZA/D), respectively. PM-CZ+D was prepared by physically mixing methanol synthesis catalyst and methanol dehydration catalyst, CP-CZA/D was prepared by depositing Cu-Zn or Cu-Zn-Al components on ${\gamma}-Al_2O_3$. The crystallinity and the surface morphology of synthesized catalyst were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) to investigate the physical property of prepared catalyst. And BET surface area by $N_2$ adsorption and the surface area of Cu by $N_2O$ chemisorption were investigated about the hybrid catalysts. In addition, catalytic activity of these hybrid catalysts was examined with varying reaction conditions. At that time, the reaction temperature of $250{\sim}290^{\circ}C$, the reaction pressure of 50~70 atm, the $[H_2]/[CO]$ mole ratio of 0.5~2.0 and the space velocity of $1,500{\sim}6,000h^{-1}$ were investigated the catalytic activity. From these results, it was confirmed that the reactivity of CP-CZA/D was higher than that of PM-CZ+D. When the conditions of reaction temperature, pressure, $[H_2]/[CO]$ ratio and space velocity were $260^{\circ}C$, 50 atm and 1.0, $3,000h^{-1}$ respectively, CO conversion using CP-CZA/D hybrid catalyst was 72% and the CO conversion of CP-CZA/D was more than 20% compared with the CO conversion of PM-CZ+D. It was known that Cu surface area of CP-CZA/D hybrid catalyst was higher than that of hybrid PM-CZ+D catalyst using $N_2O$ chemisorption. It was assumed that the catalytic activity was improved because Cu particle of hybrid catalyst prepared by precipitation method was well dispersed.