• Title/Summary/Keyword: Transferred charge density

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Transferred charge density and Optical Property on Powder Electroluminescent device (후막 EL 소자의 광학 및 이동전하밀도 특성)

  • 오주열;이종찬;박대희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.286-290
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    • 1999
  • Electroluminescence is occurred when phosphor is located in electric field. In this paper, we made powder electroluminescent device (PELD) with structured ITO film/Phosphor/Insulator/Silver paste. The transparent electrode was ITO film and green(2704-01), orange(2702-02) and blue-green(2703-01) were used as phosphor. The insulator was BaTiO$_3$ and $Y_2$O$_3$, back electrode was silver paste. To investigate electrical and optical properties of PELDs, EL spectrum, Brightness, Transferred charge density using Sawyer-Tower\`s circuit was measured.

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Interfacial Properties of a-Se Thick Films to Solve Charge Trap and Injection Problems (전하 트랩 및 주입 문제를 해결하기 위한 비정질 셀레늄 필름의 계면 특성)

  • 조진욱;최장용;박창희;김재형;이형원;남상희;서대식
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.497-500
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    • 2001
  • Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e,g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current.

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High brightness property of Power Electroluminescent Device using ZnS:Cu (ZnS:Cu를 이용한 후막 전계발광소자의 고휘도 특성)

  • Lee, Jong-Chan;Park, Dae-Hui
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.349-353
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    • 1999
  • In this paper, to fabricate the AC power electroluminescent device (PELD) with high brightness, new structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material were BaTiO3 and ZnS:Cu respectively. Fabricated AC power EL devices were estimated by optical and electrical properties of EL spectrum, brightness, CIE coordinate system, transferred charge density and EL emission wave in time domain. With above results, we found that brightness of newly proposed AC powder EL power EL device was 2754 cd/m2 at 100V, 400 Hz and compared with conventional device structure.

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Interfacial Properties of a-Se Thick Films to Solve Charge Trap and Injection Problems (전하 트랩 및 주입 문제를 해결하기 위한 비정질 셀레늄 필름의 계면 특성)

  • Cho, J.W.;Choi, J.Y.;Park, C.H.;Kim, J.H.;Lee, H.W.;Nam, S.H.;Seo, D.S.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.497-500
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    • 2001
  • Due to their better photosensitivity in X-ray, the amorphous selenium based photoreceptor is widely used on the X-ray conversion materials. It was possible to control the charge carrier transport of amorphous selenium by suitably alloying a-Se with other elements(e.g. As, Cl). The charge transport properties of amorphous Selenium is decided on hole which is induced from metal to selenium in metal-selenium junction and which is transferred in a-Se bulk. This phenomenon is resulted of changing electric field owing to increasing of space charge by deep trap of a-Se bulk. In this paper, We dopped the chlorine to compensate deep hole trap and deposited blocking layer using dielectric material to prevent from increasing space charge for injection charge between metal electrode and a-Se layer. We compared space charge and the decreasing of trap density through measuring dark and photo current. 缀Ѐ㘰〻ሀ䝥湥牡氠瑥捨湯汯杹

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Electrostatic Discharge Energy Estimation of the Charged Human Body by the Rompe-Weisel Model (Rompe-Weisel Model에 의한 대전 인체의 정전기 방전 에너지 평가)

  • 이종호;김두현;강동규
    • Journal of the Korean Society of Safety
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    • v.18 no.3
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    • pp.54-59
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    • 2003
  • The discharge energy by electrostatic discharge of the charged human body is calculated under the assumption that the stored charge is dissipated completely. However, it is well-known that the charge is slightly remained after electrostatic discharge. Therefore, The Rompe-Weisel model of the discharge analysis, which has somewhat more of a physical justification than the conventional energy equation, is proposed. It is proposed that the electrical conductivity of the arc should be proportional to the energy density transferred to it by Ohmic dissipation. For the electrostatic discharge energy analysis, the Rompe-Weisel model was compared by quasi static analysis. As a consequence, a study on a reliable energy evaluation based on simulation models during electrostatic discharge is carried out in this paper and is adopted to estimate the explosion hazards of flammable gases.

Electrical and Optical Property of Powder Electroluminescent device at Dielectric variety (절연체 종류에 따른 후막 전계 발광소자의 광학 및 전기적 특성)

  • Oh, Joo-Youl;Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1999.07d
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    • pp.1800-1802
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    • 1999
  • Electroluminescence is occurred when phosphor is located in electric field. In this paper, we made powder electroluminescent device (PELD) with structured ITO film/phosphor/Insulator/silver paste. The transparent electrode was ITO film and green(2704-01) and orange(2702-02) and blue-green(2703-01) were used as phosphor. The insulator was $BaTiO_3$ and $Y_2O_3$, back electrode was silver paste. To investigate electrical and optical properties of PELDs, EL spectrum, Brightness, Transferred charge density using Sawyer-Towers circuit was measured.

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Carbon and Silver Electrode Properties of Power Electroluminescent Device (후막 전계 발광 소자의 Carbon과 Silver 전극 특성)

  • Lee, Jong-Chan;Sung, Hyun-Ho;Cho, Whang-Sin;Park, Yong-Kyu;Park, Dae-Hee
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.04b
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    • pp.26-30
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    • 2000
  • In this paper, carbon and silver electrode properties of power electroluminescent device were investigated. Devices were manufactured by screen-printing and manufactured devices were measured following things with variable applied voltage; emission spectra, transferred charge density, brightness and current. A continuous test at $65 ^{\circ}C$ of temperature and 95% of humidity was operated. The brightness of devices which were made of silver and carbon electrode at 100V was $67.03cd/m^2$ and $60.02cd/m^2$ respectively. In case of device, which was made of silver electrode, a black spot was formed after 72 hours and degraded but carbon electrode was stable.

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A Study on Dot-Matrix Display using Powder Electroluminescent Device with High Brightness (고휘도 후막 전계발광소자을 이용한 Dot-Matrix Display에 대한 연구)

  • Lee, Jong-Chan;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 1998.07d
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    • pp.1255-1257
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    • 1998
  • In this study,$ 5{\times}5$ dot-matrix display was implemented with powder electroluminescent device (PELD). Generally PELD which have a luminance from powder phosphor with electric field, inserted phosphor and dielectric layer between electrodes is basic structure. To make high brightness PELD compared to conventional device, new type of PELD was proposed as follows. New PELD had only one layer, which was mixed phosphor (ZnS:Cu) and dielectric (BaTiO3) material appropriately between electrodes. To compare and estimate the conventional and new type of PELD, the EL spectrum, transferred charge density, brightness and decay time was measured. As above result, we fabricated a hish brightness $ 5{\times}5$ dot-matrix display with new type of PELD. Its brightness was 6400 $cd/m^2$ at 200 V, 400Hz.

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A Study on Powder Electroluminescent Device through Structure and Thickness Variation (구조 및 두께 변화에 따른 후막 전계 발광소자에 관한 연구)

  • 오주열;정병선;이종찬;박대희
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 1998.11a
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    • pp.9-11
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    • 1998
  • A phenomenon of electroluminescent radiate as electric field applied in the phosphor, in this paper, we produced the Powder Electroluminescent Device(PELD) which was changing the structure and the thickness of phosphor and insulator for realization of the PELD with high brightness. We made PELD with structure that is WK-1(ITO film/Phosphor/Insulator/Electrode), WK-2(ITO film/Phosphor/Insulator/Electro de), WK-3(ITO film/Phosphor/Insulator/Electrode), WK-4(ITO film/Phosphor+Insulator/ Electrode). The property of the produced PELD are analyzed by measuring the spectrum which electrical and optical property, the brightness and the transferred charge density. In this result, the structure of WK-4 have good luminescence property than others, it's effective thickness is 60${\mu}{\textrm}{m}$. At 100V 400Hz, High brightness of 2700cd/m2 was performed.

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A Study on Powder Electroluminescencent Device using ZnS:Cu (ZnS:CU를 이용한 후막 전계 발광소자에 관한 연구)

  • 이종찬;박대희;박용규
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1998.06a
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    • pp.121-124
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    • 1998
  • Generally the structure of powder electroluminescent devices (PELDs) on ITO-film was makeup of the ZnS:Cu phosphor layer and BaTiO$_3$ insulating layer. The active layer, which consists of a suitably doped ZnS powder mixed in a dielectric, is sandwiched between two electrodes; one of which are ITO film and the other is aluminum. In this paper, three kinds of powder eleotroluminescent devices (PELDs) : WK-A(ITO/BaTiO$_3$/ZnS:Cu/Silver paste). WK-B(ITO/BaTiO$_3$+ZnS:Cu/Silver paste) and WK-C(ITO/BaTiO$_3$/ZnS:Cu/BaTiO$_3$/Silver paste), fabricated by spin coating method, were investigated. To evaluate the luminescence properties of three kinds of PELDs, EL emission spectroscopy, transferred charge density and time response of EL emission intensity under square wave voltage driving were measured.

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