• Title, Summary, Keyword: Flat electrode method

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Surface Potential Change Depending on Molecular Orientation of Hexadecanethiol Self-Assembled Monolayers on Au(111)

  • Ito, Eisuke;Arai, Takayuki;Hara, Masahiko;Noh, Jaegeun
    • Bulletin of the Korean Chemical Society
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    • v.30 no.6
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    • pp.1309-1312
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    • 2009
  • Surface potential and growth processes of hexadecanethiol (HDT) self-assembled monolayers (SAMs) on Au(111) surfaces were examined by Kelvin probe method and scanning tunneling microscopy. It was found that surface potential strongly depends on surface structure of HDT SAMs. The surface potential shift for the striped phase of HDT SAMs chemisorbed on Au(111) surface was +0.45 eV, which was nearly the same as that of the flat-lying hexadecane layer physisorbed on Au(111) surface. This result indicates that the interfacial dipole layer induced by adsorption of alkyl chains is a main contributor to the surface potential change. In the densely-packed HDT monolayer, further change of the surface potential was observed, suggesting that the dipole moment of the alkanethiol molecules is an origin of the surface potential change. These results indicate that the work function of a metal electrode can be modified by controlling the molecular orientation of an adsorbed molecule.

Discharge Characteristics of Xe Plasma Flat Lamp for LCD Backlight According to Operating Voltage Pulse (LCD 백라이트용 Xe계 플라즈마 평판 램프의 구동 전압 Pulse의 조건에 따른 방전 특성 연구)

  • Kwon, Eun-Mi;Kim, Hyuk-Hwan;Lee, Won-Jong
    • Korean Journal of Materials Research
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    • v.13 no.4
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    • pp.271-278
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    • 2003
  • Conventional backlight for liquid crystal display (LCD) uses mercury which leads to environmental pollution. In this study, characteristics of AC coplanar type mercury-free plasma flat lamp have been studied. Pollution-free Xe-He is adopted as a discharge gas system. Since the Xe gas has a lower efficiency in generating vacuum ultraviolet (VUV) than mercury, the improvement of luminance and luminous efficiency in the Xe gas system is very important. The electrode, dielectric, and phosphor layers constituting lamp are formed on the bottom glass by the screen printing method. The effects of pulse shape, on-time, and pulse frequency on the luminance and luminous efficiency have been examined. For Xe(5%)-He gas, the lamp exhibits higher efficiency with sharper pulse shape, higher peak voltage, and shorter pulse on-time (up to 2 $\mu\textrm{s}$). Higher efficiency and lower consumption of power were obtained at 30 kHz than at 60 kHz. The collision of ion to bottom electrodes is a dominant factor to raise the lamp temperature. Therefore the high voltage and low current discharge system is necessary for reduction of the lamp temperature as well as for enhancement of the luminous efficiency.

A study on properties of ZnO:Ga thin films fabricated by RF Magnetron sputtering (RF Magnetron sputtering으로 증착한 ZnO:Ga의 특성에 관한 연구)

  • Kim, H.S.;Kim, K.B.;Koo, B.K.;Park, K.Y.;Koo, K.W.;Han, S.O.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.953-956
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    • 2003
  • Transparent conductive ZnO:Ga thin films were deposited on glass substrates using rf magnetron sputtering method for flat panel display. The ZnO:Ga films were preferentially oriented to c-axis (002) of on substrates. The surface morphology was smooth and had not porous whatever substrate temperature was. The electrical conductivity of the thin films were in the range of $1.6{\times}10^2{\sim}6.7{\times}10^3\;{\Omega}^{-1}cm^{-1}$ at the growth temperature from 50 to $400^{\circ}C$, whereas has a maximum at around $250^{\circ}C$. By combining of XRD and EXAFS, the crystallinity and grain size decreased with increasing substrate temperature corresponding to the reduction of the grain-boundary scattering. The optical transmittance of sputtered ZnO:Ga thin films had an improved about 86% in the UV-visible region.

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Tungsten Silicide ($WSi_2$) for Alternate Gate Metal in Metal-Oxide-Semiconductor (MOS) Devices (금속-산화막-반도체 소자에서 대체 게이트 금속인 텅스텐 실리사이드의 특성 분석)

  • 노관종;윤선필;양성우;노용한
    • Proceedings of the IEEK Conference
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    • pp.64-67
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    • 2000
  • Tungsten silicide(WSi$_2$) is proposed for the alternate gate electrode of ULSI MOS devices. Good structural property and low resistivity of WSi$_2$ deposited by a low pressure chemical vapor deposition(LPCVD) method directly on SiO$_2$ is obtained after annealing. Especially, WSi$_2$-SiO2 interface remains flat after annealing tungsten silicide at high temperature. Electrical characteristics of annealed WSi$_2$-SiO$_2$-Si(MOS) capacitors were improved in view of charge trapping.

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Noise Reduction Design of Plasma Display Panel (플라즈마 디스플레이의 저소음 설계)

  • Park, Dae-Kyong;Kweon, Hae-Sub;Jang, Dong-Seob
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.369.2-369
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    • 2002
  • For the evaluation of the plasma display panel (PDP)'s noise, vibration and sound characteristics of fanless PDP are measured and investigated. PDP is a type of two-electrode vacuum tube which operatres on the same principle as a household fluorescent light. An inert gas such as argon or neon is injected between two glass plates on which transparent electrodes have been formed, and the glass is illuminated by generating discharge. (omitted)

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Characteristics of indium zinc oxide thin films with input power and film thickness (투입전력 및 두께 변화 조건에 따른 Indium zinc oxide 박막의 특성)

  • Rim, You-Seung;Kim, Sang-Mo;Keum, Min-Jong;Son, In-Hwan;Jang, Kyung-Wook;Kim, Kyung-Hwan
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.406-407
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    • 2007
  • We prepared indium zinc oxide (IZO) thin film for cathode electrode such as an application of flat panel display by using the facing targets sputtering (FTS) method at room temperature. The effects of input power and film thickness were investigated with respect to physical and optical properties of films such as deposition rate, electrical properties, microstructure and transmittance. We could obtain properties of IZO thin films of under $10^{-3}\;{\Omega}-cm$ in resistivity and the thin films of over 90% in transmittance. Also, we obtained IZO thin films which were an amorphous structure.

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New Address Waveform for Improvement of the Priming Effect and the Contrast Ratio (AC-PDP에서 프라이밍 효과를 이용한 대조비 향상에 관한 연구)

  • Kwon, Shi-Ok;Kim, Ji-Sun;Joung, Bong-Kyu;Hwang, Ho-Jung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.10
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    • pp.1120-1124
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    • 2004
  • Recently, Plasma Display Panel(PDP) has been in the spotlight as one of the next generation flat-panel-display device. However, it has several drawbacks like the low contrast ratio and the low luminance. In this study, a new address waveform is suggested to improve the priming effect and contrast ratio at the address period in the Address Display period Separated(ADS) method. We modified waveform, instead of a conventional waveform, to an address period, for operating on the Plasma Display Panels, which used the conventional gas [He-Ne-Xe〕. When the ramp pulse is added to the address period at the sustain electrode, it is improved on the priming effect and contrast ratio.

A Study of Seam Tracking by Arc Sensor Using Current Area Difference Method (전류 면적차를 이용한 아크 센서의 용접선 추적에 관한 연구)

  • 김용재;이세헌;엄기원
    • Journal of Welding and Joining
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    • v.14 no.6
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    • pp.131-139
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    • 1996
  • The response of the arc sensor using the welding current and/or welding voltage as its outputs has been obtained by the analysis and/or experiments of the static characteristics of arc sensor. But in order to improve the reliability of arc sensor, it is necessary to know its dynamic characteristics. So in this paper, it is presented the dynamic model of arc sensor including the power source, arc voltage, electrode burnoff rate, and wire feed rate. A numerical simulation of the dynamic model of arc sensor was implemented, computing the welding current with input of CTWD. The results of computer simulations and experiments of $CO_2$arc welding showed that a linear relationship between weaving center - weld line distance and current area difference was established. Additionally, a real-time weld seam tracking system interfaced with industrial welding robot was constructed, the result of the weld seam tracking experiment for weld line with an initial offset error of 5$^{\circ}$was good.

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A Study on the Characteristics of ITO Thin Film for Top Emission OLED (Top Emission OLED를 위한 ITO 박막 특성에 대한 연구)

  • Kim, Dong-Sup;Shin, Sang-Hoon;Cho, Min-Joo;Choi, Dong-Hoon;Kim, Tae-Geun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.450-450
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    • 2006
  • Organic light-emitting diodes (OLED) as pixels for flat panel displays are being actively pursued because of their relatively simple structure, high brightness, and self-emitting nature [1, 2]. The top-emitting diode structure is preferred because of their geometrical advantage allowing high pixel resolution [3]. To enhance the performance of TOLEDs, it is important to deposit transparent top cathode films, such as transparent conducting oxides (TCOs), which have high transparency as well as low resistance. In this work, we report on investigation of the characteristics of an indium tin oxide (ITO) cathode electrode, which was deposited on organic films by using a radio-frequency magnetron sputtering method, for use in top-emitting organic light emitting diodes (TOLED). The cathode electrode composed of a very thin layer of Mg-Ag and an overlaying ITO film. The Mg-Ag reduces the contact resistivity and plasma damage to the underlying organic layer during the ITO sputtering process. Transfer length method (TLM) patterns were defined by the standard shadow mask for measuring specific contact resistances. The spacing between the TLM pads varied from 30 to $75\;{\mu}m$. The electrical properties of ITO as a function of the deposition and annealing conditions were investigated. The surface roughness as a function of the plasma conditions was determined by Atomic Force Microscopes (AFM).

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Application of Inkjet Technology in Flat Panel Display

  • Ryu, Beyong-Hwan;Choi, Young-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.913-918
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    • 2005
  • It is expected that the inkjet technology offers prospect for reliable and low cost manufacturing of FPD (Flat Panel Display). This inkjet technology also offers a more simplified manufacturing process for various part of the FPD than conventional process. For example, recently the novel manufacturing processes of color filter (C/F) in LCD, or RGB patterning in OLED by inkjet printing method have been developed. This elaborates will be considered as the precious point of manufacturing process for the mass production of enlarged-display panel with a low price. On this point of view, we would like to review the status of inkjet technology in FPD, with some results on forming micro line by inkjet patterning of suspension type silver nano ink as below. We have studied the inkjet patterning of synthesized aqueous silver nano-sol on interface-controlled ITO glass substrate. Furthermore, we designed the conductive ink for direct inkjet patterning on bare ITO glass substrate. The first, the highly concentrated polymeric dispersant-assisted silver nano sol was prepared. The high concentration of batch-synthesized silver nano sol was possible to 40 wt%. At the same time the particle size of silver nanoparticles was below $10{\sim}20nm$. The second, the synthesized silver nano sol was inkjet - patterned on ITO glass substrate. The connectivity and width of fine line depended largely on the wettability of silver nano sol on ITO glass substrate, which was controlled by surfactant. The relationship was understood by wetting angle. The line of silver electrode as fine as $50{\sim}100\;{\mu}m$ was successfully formed on ITO glass substrate. The last, the direct inkjet-patternable silver nano sol on bare ITO glass substrate was designed also.

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