• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1733-1735
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• 2000

평판 디스플레이 소자인 후막 전계발광소자는 평판형 조명부터 LCD 백라이트에 응용되고 있다. 후막 전계발광소자에 사용되는 ZnS:Cu 형광체는 저주파수에서는 녹색 발광을 하며, 고주파수에서는 청색 발광을 가진다. 본 연구는 저주파수에서도 청색을 가지는 소자를 제작하기 위하여 형광체와 염료의 혼합 비율에 따른 발광특성을 조사하였다. 염료의 혼합 비율은 0$\sim$5 wt%로 하였다. 소자의 발광현상을 고찰하기 위하여 발광 스펙트럼과 휘도를 측정하였다.

• Proceedings of the KAIS Fall Conference
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• 2000.04a
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• pp.85-85
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• 2000

• 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.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.49-52
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• 1998

In this paper, to implement the electrical equivalent modeling of powder electroluminescent device, capacitate equation of device was chosen. The conventional structure device which have dielectric and phosphor layer between electrodes, and the single emission structure device which means that dielectric and phosphor were mixed between electrodes, were investigated. As a result, it was possible to make the equation that is transferred capacitance to phosphor layer, and using measured brightness efficiency and conductivity of devices was calculated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.407-407
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• 2008

무기EL 디스플레이는 고체재료에 전계를 가했을 때 발광하는 현상을 이용한소자로서, 급속도로 발전을 거듭하고 있으나, 유전체층에 강한전계를 가하여 발광하여야 하므로 낮은 Breakdown voltage와 효율의 한계로 인하여 휘도가 낮고 풀 컬러화 디스플레이 등 의 응용에는 적용되고 있지 못하는 실정이다. 본 연구에서는 강유전체 Perovskite 구조를 가지는 ABO3 물질 중 PMN(Lead Magnesium niobate) 과 PZT (Lead Zirconate titanate) 후막을 제조하여 Inorganic EL(Electro Luminance)에 적용하고 소자의 광전특성을 평가하였다. 소자에 사용된 기판은 고온소성에 알맞은 알루미나(Al2O3)기판을 채택 하였으며, 그 위 하부전극으로는 고온소성에 따른 화학적 안정성이 우수한 Au전극을 Screen Printing 하였다. 제조 되어진 PMN후막 페이스트는 PMN(Pb(Mg1/2 Nb2/3)O3) + Glass Frit(Pb-Zn-B) + BaTiO3(99.99%) 로 합성되었으며 하부전극위에 인쇄하였다. 그 다음 PZT sol-gel을 Spin coating으로 도포 하였다. 형광체로 ZnS:Cu.Cl 을 Screen Printing을로 형성하였으며, 평탄화를 위하여 유기물 충을 Screen Printing 공정으로 성막 하였다. 상부전극으로는 DC sputter로 ITO를 증착하여 EL소자 완성 후 Spectro - Chroma meter로 소자특성을 측정하였다. 평탄화를 통한 유기물층에 변화되는 Capacitance를 Oscilloscope로 전압 전류 pulse의 변화에 따른 opto-electronic 특성을 평가하였다.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1797-1799
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• 1999

In this paper, to implement the electrical equivalent modeling of powder electroluminescent device, capacitate equation of device was chosen. The conventional structure device which have dielectric and phosphor layer between electrodes, and the single emission structure device which means that dielectric and phosphor were mixed between electrodes, were investigated. As a result, It was possible to make the equation that is transferred capacitance to phosphor layer, and using measured brightness efficiency and conductivity of devices was calculated.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1526-1528
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• 1999

In this papaer, 7-segment was implemented using AC powder EL. ZnS:Cu and $BaTiO_3$ was used as a phosphor and dielectric respectively. The preparation of phosphor and dielectic layer was performed with screen printing. The implemented system of 7-segment was divided as following; EL display. driving circuit. software for driving. The properties of fabricated devices was measured with EL spectrum. brightness and J-V.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1382-1384
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• 1998

Electroluminescence is occurred when phosphor is located in electric field. Object of this research show new type of powder electroluminescent device (PELD) for high brightness compared with conventional PELD. New type of PELD structured as follow ITO/phosphor + dielectric/Silver paste). To investigate optical properties of PELDs, EL spectrum, CIE coordinate system, Brightness of PELDs was measured. The suitable ratio between phosphor and dielectric in new type of PELD was 7:3(phosphor:dielectric). At 200 V 400 Hz, new type of PELD which had ratio of 7:3 was 5700 cd/$m^2$.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1730-1732
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• 2000

Powder Electroluminescent Device is the solid state device which has a low power consumption, large area emission with uniformity, easy manufacturing, simple structure, and flexible mechanically. In this paper, we made the information display with the powder electroluminescent device using back-light and designed the driving circuit.

• 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.