• Title/Summary/Keyword: Secondary electron emission coefficient

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Surface Discharge Characteristics of New Flat Fluorescent Lamp Enhanced by MgO Nano-Crystals

  • Lee, Yang-Kyu;Heo, Seung-Taek;Lee, You-Kook;Lee, Dong-Gu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.687-690
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    • 2009
  • It has been recently reported that nano-sized MgO single crystal powders emit ultraviolet by stimulation of electrons under vacuum condition. Therefore, in this study, nano-crystalline MgO powders were applied to a xenon plasma flat fluorescent lamp for LCD backlight to improve emission efficiency of the lamp by help of extra ultraviolet from nano-MgO. For comparison with nano-crystalline MgO powders, MgO nano-thin film was applied directly on phosphors inside a lamp panel through e-beam evaporation The luminance and efficiency of FFL with an addition of MgO nano-crystal powders on phosphors were improved by around 20%. Application of MgO thin film to phosphors worsened the emission characteristics of FFLs, even rather than FFL without MgO. The reason came from insufficient stimulation of phosphors by UV, crystallinity of MgO, and low secondary electron coefficient.

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Properties of Indium Tin Oxide Thin Films According to Oxygen Flow Rates by γ-FIB System (γ-FIB 시스템을 이용한 산소 유량 변화에 따른 산화인듐주석 박막의 특성 연구)

  • Kim, D.H.;Son, C.H.;Yun, M.S.;Lee, K.A.;Jo, T.H.;Seo, I.W.;Uhm, H.S.;Kim, I.T.;Choi, E.H.;Cho, G.S.;Kwon, G.C.
    • Journal of the Korean Vacuum Society
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    • v.21 no.6
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    • pp.333-341
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    • 2012
  • Indium Tin Oxide (ITO) thin films were prepared by RF magnetron sputtering with different flow rates of $O_2$ gas from 0 to 12 sccm. Electrical and optical properties of these films were characterized and analyzed. ITO deposited on soda lime glass and RF power was 2 kW, frequency was 13.56 MHz, and working pressure was $1.0{\times}10^{-3}$ Torr, Ar gas was fixed at 1,000 sccm. The transmittance was measured at 300~1,100 nm ranges by using Photovoltaic analysis system. Electrical properties were measured by Hall measurement system. ITO thin films surface were measured by Scanning electron microscope. Atomic force microscope surface roughness scan for ITO thin films. ITO thin films secondary electron emission coefficient(${\gamma}$) was measured by ${\gamma}$-Focused ion beam. The resistivity is about $2.4{\times}10^{-4}{\Omega}{\cdot}cm$ and the weighted average transmittance is about 84.93% at 3 sccm oxygen flow rate. Also, we investigated Work-function of ITO thin films by using Auger neutralization mechanism according to secondary electron emission coefficient(${\gamma}$) values. We confirmed secondary electron emission peak at 3 sccm oxygen flow rate.

Characteristics of Molecular Band Energy Structure of Lipid Oxidized Mammalian Red Blood Cell Membrane by Air-based Atmospheric Pressure Dielectric Barrier Discharge Plasma Treatment

  • Lee, Jin Young;Baik, Ku Youn;Kim, Tae Soo;Jin, Gi-Hyeon;Kim, Hyeong Sun;Bae, Jae Hyeok;Lee, Jin Won;Hwang, Seung Hyun;Uhm, Han Sup;Choi, Eun Ha
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.262.1-262.1
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    • 2014
  • Lipid peroxidation induces functional deterioration of cell membrane and induces cell death in extreme cases. These phenomena are known to be related generally to the change of physical properties of lipid membrane such as decreased lipid order or increased water penetration. Even though the electric property of lipid membrane is important, there has been no report about the change of electric properties after lipid peroxidation. Herein, we demonstrate the molecular energy band change in red blood cell membrane through peroxidation by air-based atmospheric pressure DBD plasma treatment. Ion-induced secondary electron emission coefficient (${\gamma}$ value) was measured by using home-made gamma-focused ion beam (${\gamma}$-FIB) system and electron energy band was calculated based on the quantum mechanical Auger neutralization theory. The oxidized lipids showed higher gamma values and lower electron work functions, which implies the change of surface charging or electrical conductance. This result suggests that modified electrical properties should play a role in cell signaling under oxidative stress.

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Influence of constraint MgO deposition onto phosphors on luminance properties in AC Plasma Display Panels

  • Jeoung, Jin-Man;OH, P.Y.;Moon, M.W.;Lee, J.H.;Jeong, J.E.;Lee, H.J.;Han, Y.K.;Lee, S.B.;Jeong, S.H.;Yoo, C.K.;Yoo, N.R.;Choi, E.H.;Ko, B.D.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1215-1217
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    • 2005
  • One of the important problems in recent AC-PDP technology is the image sticking. In this research, we have investigated the PDP cell with constraint deposition MgO on phosphor, the electrical and optical properties in the PDP cell were examined. Also, we have investigated the correlation with image sticking and degraded MgO protective layer, phosphor in AC-PDP. As a result, we measured the secondary electron emission coefficient ${\gamma}$, discharge characteristics and Brightness for the constraint degraded phosphor are compared with those of nondegraded phosphor.

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Structural and discharge characteristics of MgO films prepared by Arc Ion Plating (AIP) method

  • Kim, Jong-Kuk;Kim, Do-Geun;Lee, Eun-Sung;Lee, Sung-Hun;Lee, Gun-Hwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.625-627
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    • 2002
  • MgO thin films were deposited on glass and (100) Si substrates by an Arc Ion Plating (AIP) equipment using a magnesium metal target at various oxygen gas flow. In this work, we investigated the relationship between the structural properties and the discharge characteristics of MgO coating layers. X-ray diffraction and AFM have been used to study behaviors of the structure and surface morphology. The optical transmittance and the ion induced secondary electron emission coefficient of the MgO films have been also measured. The resistivity of the deposited MgO films was gradually increased from 0.17 G ohm/${\square}$ to 0.35 G ohm/${\square}$ with the oxygen gas flow. The growth rate of the MgO coating layer was decreased with increasing the oxygen gas flow, while the optical transmittance was improved.

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A Study on the Discharge Characteristics and Optimum Activation Conditions of MgO Thin Film in AC POP (AC PDP의 MgO 활성화 조건과 그 방전 특성에 관한 연구)

  • Kim, Young-Kee;Kim, Suk-Ki;Park, Byung-Yun;Park, Myung-Joo;Cho, Jung-Soo;Park, Chung-Hoo
    • Proceedings of the KIEE Conference
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    • 1998.07e
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    • pp.1758-1760
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    • 1998
  • MgO Protecting layer in AC PDP prevents ion bombardment in discharge plasma. The MgO layer also has the additional importance in lowering the firing voltage due to a large secondary electron emission coefficient. Until now, the MgO protecting layer is mainly prepared by E-beam Evaporation. However, the optimum activation manufacturing process of MgO thin film wasn't well known. Therefore in this study, after MgO protecting layer is prepared on dielectric layer by E-beam evaporation and liquid MgO spin coating, we carried out activation process of MgO thin film as a parameter of Temperature, Operating time and Operating pressure. In addition, discharge characteristics are also studied as a parameter of activation conditions.

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Effects of Fe2O3 Addition on Optical and Electrical Properties of MgO Films as a Protective Layer for AC PDPs (Fe2O3 첨가에 따른 AC PDP 보호막용 MgO 박막의 광학적.전기적 특성)

  • Kim, Chang-II;Jeong, Young-Hun;Lee, Young-Jin;Paik, Jong-Hoo;choi, Eun-Ha;Jung, Seok;Kim, Jeong-Seok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.9
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    • pp.760-765
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    • 2009
  • The effects of $Fe_2O_3$ addition on optical and electrical properties of MgO films as a protective layer for AC plasma display panels were investigated. Doped MgO films prepared by the e-beam evaporation have a higher ${\gamma}$ (secondary electron emission coefficient) than pure MgO protective layer. Roughness increased with amount of $Fe_2O_3$ up to 100 ppm and then decreased further addition. These results showed that discharge properties and optical properties of MgO protective layers seemed to be closely related with microstructure factors such as roughness. Good optical and electrical properties of ${\gamma}$ of 0.120, surface roughness of 14.1 nm and optical transmittance of 94.55% were obtained for the MgO + 100 ppm $Fe_2O_3$ protective layer sintered at $1700^{\circ}C$ for 5 hrs.

A Study on the Equipment of Neutral Beam Assisted Deposition for MgO Protective Layer of High Efficient AC PDP (고효율 AC PDP용 MgO 보호막 형성을 위한 중성빔 보조 증착 장비에 관한 연구)

  • Li, Zhao-Hui;Kwon, Sang-Jik
    • Journal of the Semiconductor & Display Technology
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    • v.7 no.2
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    • pp.63-67
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    • 2008
  • The MgO protective layer plays an important role in plasma display panels (PDPs). Our previous work demonstrated that the properties of MgO thin film could be improved, which were deposited by ion beam assisted deposition (IBAD). However arc discharge always occurs during the IBAD process. To avoid this problem, oxygen neutral beam assisted deposition (NBAD) is used to deposit MgO thin films in this paper. The energy of the oxygen neutral beam was used as the parameter to control the deposition. The experimental results showed that the oxygen neutral beam energy was effective in determining in F/$F^+$ centers, crystal orientation, surface morphology of the MgO thin film, and the discharge characteristics of AC PDP. The lowest firing voltage $(V_f)$ and the highest secondary electron emission coefficient $(\gamma)$ were obtained when the neutral beam energy was 300 eV.

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Fabrication of Atmospheric Coplanar Dielectric Barrier Discharge and Analysis of its Driving Characteristics (평면형 대기압 유전장벽방전장치의 제작 및 동작특성분석)

  • Lee, Ki-Yung;Kim, Dong-Hyun;Lee, Ho-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.1
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    • pp.80-84
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    • 2014
  • The discharge characteristics of Surface Dielectric Barrier Discharge (SDBD) reactor are investigated to find optimal driving condition with adjusting various parameter. When the high voltage with sine wave form is applied to SDBD source, successive pulsed current waveforms are observed owing to multiple ignitions through the long discharge channel and wall charge accumulation on the dielectric surface. The discharge voltage, total charge between dielectrics, mean energy and power are calculated from measured current and voltage according to electrode gap and dielectric thickness. Discharge mode transition from filamentary to diffusive glow is observed for narrow gap and high applied voltage case. However, when the diffusive discharge is occurred with high applied voltage, the actual firing voltage is always lower than that with low driving voltage. The $Si_3N_4$, $MgF_2$, $Al_2O_3$ and $TiO_2$ are considered for dielectric protection and high secondary electron emission coefficient. SDBD with $MgF_2$ shows the lowest breakdown voltage. $MgF_2$ thin film is proposed as a protection layer for low voltage atmospheric dielectric barrier discharge devices.