• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.51-54
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• 2007

Top-emission 3.5 inch qVGA IOD (Inverted AMOLED) was fabricated with inverted EL structure driven by a-Si TFT backplane. In order to get stable driving TFT, we used FCP(Field Control Plate) layer which was connected with the source of the driving TFT. And we developed planarization process to planarize the cathode layer which was the bottom layer of inverted OLED. Our unique IOD structure is “a-Si TFT/ Al(Cathode)/ LiF/ LG-201(ETL)/ EML(RGB)/ HTL/ LG-101(HIL & Buffer layer)/ IZO(Anode)”. LG-201(ETL) layer was studied for more efficient electron injection from cathode to EML, and LG-101(HIL & Buffer layer) covered by IZO anode was also explored for decreasing the EL surface damage.

• 반도체디스플레이기술학회지
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• 제21권3호
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• pp.39-44
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• 2022

The light extraction technology for improving the light efficiency of OLEDs is the core technology for extracting the light inside the OLEDs to the outside. This study demonstrates a simple method to generate random nanostructures (RNSs) containing high refractive index nanoparticles to improve light extraction and viewing angle characteristics. A simple dry low-temperature process makes the nanostructured scattering layer on the polymer resin widely used in the industry. The scattering layer has the shape of randomly distributed nanorods. To control optical properties, we focused on changing the shape and density of RNSs and adjusting the concentration of high refractive index nanoparticles. As a result, the film of the present invention exhibits a perpendicular transmittance of 85% at a wavelength of 550 nm. This film was used as a scattering layer to reduce substrate mode loss and improve EL efficiency in OLEDs.

• 반도체디스플레이기술학회지
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• 제5권3호
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• pp.1-4
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• 2006

White-light-emitting ZnS:Mn, Cu, Cl phosphors with spherical shape and the size of $20\;{\mu}m$ are successfully synthesized. They have the double phases of cubic and hexagonal structures. They are applied to electroluminescent (EL) devices by silk screen method with the following structure: $electrode/BaTiO_3$ insulator layer ($50{\sim}60\;{\mu}m$)/ ZnS:Mn, Cu, Cl phosphor layer ($30{\sim}50\;{\mu}m$)/ITO glass. The EL devices are driven with the voltage of 100 V and the frequency of 400 Hz. The EL devices show the three emission peaks. The blue and green emission bands are originated from $CICu^{2+}$ transition and $ClCu^+$ transition, respectively. The yellow emission band results from $^4T^6A$ transition of $Mn^{2+}$ ion. As an increase of Cu concentrations, the blue and green emission intensities decrease whereas the yellow emission intensity increases; the quality becomes warm white. It is due to the energy transfer from the blue and green bands to the yellow band.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.356-363
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• 2007

전계발광(EL) 소자 제조용 액상 페이스트 용액의 안정성은 사용한 안정화제의 종류 및 첨가량에 크게 영향을 받았으며, 본 실험에서 사용한 안정화제 중에서 Disperbyk-180이 형광체 액상 페이스트에 대하여 넓은 첨가량 범위에서 90일 이상의 안정성을 보였다. 안정화제 Disperbyk-180을 형광체 및 유전체 페이스트 용액에 첨가하여 인쇄 실험을 수행한 결과, 층분리 현상은 일어나지 않았으며, 균일도는 기존 사용 페이스트 보다 우수한 것으로 나타났고 인쇄 시 기포 발생과 점도 변화가 매우 작았다. 특히 형광체 페이스트의 경우 균일성과 휘도가 기존의 페이스트에 비하여 상당히 향상되었으며, ITO 기판과의 접착성도 우수하였다. 안정화제 Disperbyk-180이 첨가된 페이스트를 사용하여 제조한 EL 소자는 100 V, 400 Hz에서 $57.6cd/m^2$의 휘도를 나타내었으며, 주파수 변화에 따라서 급격한 휘도 변화는 나타내지 않았다. 또한 EL 소자의 수명을 측정한 결과 반감기는 1,250시간으로 외국에서 수입되어 시판되고 있는 페이스트를 사용한 경우와 유사한 수명을 나타내었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.623-625
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• 2004

In Electro-Luminescence Display making process, it is necessary to do high molecule patterning effectively. Recently, one of the most effective way is the patterning method using Ink-Jet head controller. To maximize the effect, it is needed to control each channel of Ink-Jet head and develop that controller. Thus, we implement the Ink-Jet Head Controller which can control the parameters of 128 fire pulses independently, improve the accuracy of patterns more than 100 times previous ones, and apply random patterns.

• 반도체디스플레이기술학회지
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• 제8권4호
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• pp.37-42
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• 2009

The performance of an OLED(organic luminescent emitting device) fabrication system strongly depends on the design of the evaporation cell-source. Trends in display sizes have hauled the enlargement of mother glass substrates. The enlargement of substrates requires the improvement and the enlargement of the effusion cell-source for OLED evaporation process. The deposited layers should be as uniform as possible, and therefore it is important to know the effusion profile of the molecules emitted from the cell-source. Conventional 2D DSMC algorithm cannot be used for simulating the new concept cell-source design, such as a linear source. This work concerns the development of 3D DSMC (direct simulation Monte Carlo) analysis for simulating the behavior of the evaporation cell-sources. In this paper, the 3D DSMC algorithm was developed and the film thickness profiles were obtained by the numerical analysis.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.243-252
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• 2002

We propose a new concept: that of photonic crystal phosphors (PCPs) for display and phosphor related applications. It is well known that microcavities with dimensions comparable to the emitting wavelength strongly enhance light-matter interactions, resulting in a significant increase in spontaneous emission rate, which can be directly translated into enhancement in phosphor efficiency. In recent simulations we have demonstrated that when a microcavity is formed in a nano-phosphor structure, the luminescence band is modified, and can be made spectrally sharp and tunable by engineering the geometry/material properties of the cavity and the surrounding photonic crystal lattice. New phosphor material structures based on photonic crystals are proposed. Applications to thin film EL phosphors and particle phosphors are discussed. Additionally, economic methods of synthesizing and incorporating PCPs into current display applications are proposed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
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• pp.325-328
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• 2002

We developed a high performance 2.2" active matrix OLED display for IMT-2000 mobile phone. Scan and Data driver circuits were integrated on the glass substrate, using low temperature poly-Si(LTPS) TFT CMOS technology. High efficiency EL materials were employed to the panel for low power consumption. Peak luminescence of the panel was higher than 250cd/$m^2$ with power consumption of 200mW.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.302-305
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• 1995

ITO(indium tin oxide) that is both conductive in electricity and transparent to the visible ray is called transparent conducting thin film. Nowaday, according to the development of flat panel display such as LCD(Liquid Crystal display, EL(electolumine- scence display), PDP(plasma display panel), ECD(electrocromic display), the higher quality in the low temperature process has been asked to reduce the production cost and to have a good uniformity on a large substrate. In this study, we prepared indium tin oxide(ITO) by a cylindrical DC magnetron sputtering with Indium-tin (9:1) alloy target instead of indium-tin oxide target. To reduce the defact in ITO, the effect on ITO by varing the magnetic field intensity and the applied voltage ares studied. the resistivity of the film deposited in oxygen partial pressure of 5% and substrate temperature of 140$^{\circ}C$. is 1.6${\times}$10$\^$-1/$\Omega$$.$cm with 85% optical transmission in viaible ray.

• Journal of Information Display
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• 제3권2호
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• pp.1-5
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• 2002

A CMOS driving circuit for active matrix type polymer electroluminescent displays was designed to develop an on-chip microdisplay on the single crystal silicon wafer substrate. The driving circuit is a conventional structure that is composed of the row, column and pixel driving parts. 256 gray scales were implemented using pulse amplitude modulation method. The 2-transistor driving scheme was adopted for the pixel driving part. The layout was carried out considering the compatibility with the standard CMOS process. Judging from the layout of the driving circuit, it turns that it is possible to implement a high-resolution display about 400 ppi resolution. Through the HSPICE simulation, it was verified that this circuit is capable of driving a VGA signal mode display and implementing 256 gray levels.