• 제목/요약/키워드: Surface coverage

검색결과 494건 처리시간 0.022초

Hole Injection Layer by Ion Beam Assisted Deposition for Organic Electroluminescence Devices

  • Choi, Sang-Hun;Jeong, Soon-Moon;Koo, Won-Hoe;Baik, Hong-Koo
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.II
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    • pp.1619-1622
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    • 2005
  • The ultra thin hole injection layer (HIL) was deposited on an indium-tin-oxide (ITO) anode by using an ion beam assisted d eposition (IBAD) for the fabrication of an polymeric electroluminescence device for the first time. The device with the HIL deposited by IBAD has higher external quantum efficiency than the device with the HIL by conventional thermal evaporation. It is found that the deposited HIL by IBAD has high surface coverage on ITO anode in a few nm regions because the HIL prepared has high adatom mobility by ion beam energy.

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Initial state of GaN grown by plasma enhanced molecular beam epitaxy (PEMBE로 성장된 GaN 박막의 초기 거동 관찰)

  • Yi, Min-Su;Cho, Tae-Sik
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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    • pp.989-992
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    • 2004
  • PEMBE(plasma enhanced molecular beam epitaxy)방법으로 성장된 GaN 박막의 초기 거동현상을 실시간 X-선 산란을 이용하여 관찰하였다. 표면이 원자 계단(atomic step)을 이루고 있는 사파이어 기판 위에 성장하는 GaN 박막은 layer-by-layer 모드로 성장 후 3D 모드로 성장을 하였다. 거친 표면을 가진 사파이어 기판 위에 성장하는 GaN 박막은 성장 초기는 표면을 평평하게 만든 후, 3D 모드로 성장하였다. 플라즈마로 생성된 이온화된 질소는 표면의 에너지를 변화시켜 GaN 박막의 증착을 증진시키고, 표면의 coverage를 증가시킨다.

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Characteristic Analysis of $Al_2$O$_3$Thin Films Grown by Atomic Layer Deposition (ALD법으로 성장시킨 $Al_2$O$_3$ 박막의 특성분석)

  • 성석재;김동진;배영호;이정희
    • Proceedings of the IEEK Conference
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    • 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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    • pp.185-188
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    • 2001
  • In this study, $Al_2$O$_3$films have been deposited with Atomic Layer Deposition(ALD) for gate insulator for MPTMA and $H_2O$ at low temperature below 40$0^{\circ}C$ . Conventional methods of $Al_2$O$_3$thin film deposition have suffered from the poor step coverage due to reduction of device dimension and increasing contact/via hole aspect ratio. ALD is a self-limiting growth process with controlled surface reaction where the growth rate is only dependent on the number of growth cycle and the lattice parameter of materials. ALD growth process has many advantages including accurate thickness control, large area and large batch capability, good uniformity, and pinholes freeness.

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Water Quality Improvement by Artificial Floating Island (인공섬을 이용한 소형 저수지의 수질 개선)

  • Park, Hyun-Jin;Kwon, Oh-Byeong;Ahn, Tae-Seok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • 제4권1호
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    • pp.90-97
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    • 2001
  • For improvement of water quality, $20m^2$ of artificial floating plant islands planted with Iris pseudoacorus, were installed in small pond on March, 1999. Small pond has surface area $1,000m^2$ and mean depth 1.5 m. The density of plants was 16 per $m^2$ by using jute pot. Environmental parameters such as COD, SS, T-N, T-P and planktons were biweekly measured from 29 March to 28 September. Because of the small portion of floating island, the effect for water quality improvement was not sufficient. But considering the data of plant growth and nitrogen and phosphorus uptake capacity of plant, about 40% of coverage by artificial floating island was needed for elimination of whole nutrients from inflow.

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Air Temperature Variation by Effect of Green Space Distribution (녹지분포에 따른 기온변화)

  • Yoon, Yong-Han
    • Journal of the Korean Society of Environmental Restoration Technology
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    • 제5권2호
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    • pp.47-52
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    • 2002
  • In this study, in order to find out relationship of green space distribution and lower air temperature effect, observed air temperature distribution in and out green space in the cloudy. On basis of the result, we are analyzed relationship of air temperature distribution in and out green space, of green space distribution and air temperature of, lower air temperature effect and the urban in between the green space by using regression analysis. According to the result, the higher temperature zone formed around urban, and the lower temperature zone was similar to shape of green space. In case of the green space, higher temperature zone is formed around paved surface and barren ground, lower temperature zone is done forest and water area. To compare air temperature of windward and leeward around green space, the windward formed the lower temperature zone and although the wind direction is not the leeward to the green space, air temperature formed lower temperature zone to the urban in between the green space.

Electrochemical Impulse Oscillations at the Platinum Group Electrode Interfaces (백금족 전력 계면에서 전기화학적 Impulse 발진)

  • 전장호;손광철;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
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    • 제32A권3호
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    • pp.143-151
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    • 1995
  • The electrochemical impulse oscillations of the cathodic currents at the platinum group (Pt, Pd) electrode/(0.05M KHC$_{8}H_{4}O_{4}$) buffer solution interfaces have been studied using voltammetric, chronoamperometric, and electrochemical impedance methods. The periodic impulses of the cathodic currents are the activation controlled currents due to the hydrogen evolution reaction, and depend on the fractional surface coverage of the adsorbed hydrogen intermediate and potential. The oscillatory mechanism of the cathodic current impulses is connected with the unstable steady state of negative differential resistance. The widths and periods of the cathodic current impulses are 4ms or 5ms and 152.5ms or 305ms, respectively. The H$^{+}$ discharge reaction step is 38 or 61 times faster thatn the recombination reaction steps and the H$^{+}$ mass transport processes. The atom-atom recombination reaction step is twice faster thatn the atom-ion recombination reaction step. The two kinds of active sites corresponding to the atom-atom and atom-ion recombination reaction steps exist on the platinum group electrode surfaces.

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Atomic Layer Etching of Silicon Using a Ar Neutral Beam of Low Energy (저에너지의 Ar 중성빔을 이용한 Silicon의 Atomic Layer Etching)

  • Oh, Chang-Kwon;Park, Sang-Duk;Yeom, Geun-Young
    • Korean Journal of Materials Research
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    • 제16권4호
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    • pp.213-217
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    • 2006
  • In this study, atomic layer etching of Si has been carried out using $Cl_2$ adsorption followed by the irradiation Ar neutral beam of low energy. In this experiment, the etch rate of Si was dependent on the $Cl_2$ pressure(the surface coverage of chlorine) and the irradiation time of Ar neutral beam(the flux density of Ar neural beam). And the etch rate of Si(100) and Si(111) were saturated exactly at one monolayer per cycle with $1.36{\AA}/cycle\;and\;1.57{\AA}/cycle$, respectively.

Characteristics of 10-day composite NDVI and LAI in Korea Peninsula Using NOAA AVHRR Data (NOAA AVHRR데이터를 이용한 한반도의 순별 NDVI와 LAI 특성)

  • Park, Jong-Hwa;Jun, Taek-Ki;Na, Sang-Il;Park, Min-Seo
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 한국농공학회 2005년도 학술발표논문집
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    • pp.649-654
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    • 2005
  • This study proposes a particular approach to assess information about NDVI(Normalized Difference Vegetation Index) and LAI(Leaf Area Index) from the spectroradiometer and NOAA/AVHRR satellite data. AVHRR data were collected in twelves months over a one year period in 2004. We calculated 10-day composite NDVI using daily composite AVHRR surface reflectance products(1km spatial resolution). The 10-day composite NDVI have a great effect on the plant growth conditions. Considerably, NDVI was increased by developing muscle fiber tissue from April to May. Then the NDVI increased until the August and then decreased until February. The highest month was at August and the lower month was at December. The difference NDVI analysis using December and another months data was conducted, the results were provided information on the variation of vegetation coverage. The result suggest that a relationship established between the LAI and NDVI in 2004.

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Effect of $BaTiO_3$ Dispersion on the Properties of Cast Tapes in Processing of Multilayer Ceramic Capacitor(MLCC) (적층 세라믹콘덴서 제조공정에서 $BaTiO_3$의 분산이 테이프캐스팅 성형체의 물성에 미치는 영향)

  • 김봉호;김병관;김명호;백운규
    • Journal of the Korean Ceramic Society
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    • 제33권2호
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    • pp.214-222
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    • 1996
  • The effect of physicochemical properties of organic solvent and dispersant among organic solvent dispersant binder and plasticizer which are used as processing additives in MLCC fabrication process on the dispersion of BaTiO3 was studied. The steric and electrostatic stabilization mechanisms in dispersion of BaTiO3 in organic media were evaluated respectively. The sttability of BaTiO3 achieved bysteric stabilization was dependent on the fraction of surface coverage of dispersant adsorption on BaTiO3. The electrostatic repulsive forces of BaTiO3 particles dispersed in orgainc media was found to be appreciabley great and dependent mainly on the kinds of organic solvent used. The mechanism affecting the stability of BaTiO3 was studied by the method of rheologi-cal behaviors of BaTiO3 suspension.

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Effects of nano silver contents on screen printed-etched gate electrodes and electrical characteristics of OTFTs

  • Lee, Mi-Young;Park, Ji-Eun;Song, Chung-Kun
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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    • pp.917-919
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    • 2009
  • Effects of nano-silver contents(15~50wt%) on screen printed-etched gate electrodes and electrical characteristics of OTFTs were investigated. As Ag contents increased, the screen-printed film was transferred exactly without spreading and obtained the densely-packed layer with a stable and excellent conductivity but, its thickness was increased and surface became rougher. It was found that the leakage current of MIM devices and off-state currents of OTFTs became larger due to poor step coverage of PVP dielectric layer on the thick and rough gate electrodes for nano-Ag inks with Ag contents more than 30wt%.

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