• Journal of Information Display
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• v.7 no.3
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• pp.23-26
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• 2006

We fabricated top emission organic light emitting diode (TEOLED) with transparent metal cathode Barium and Silver bilayer. Very thin Ba/Ag bilayer was deposited on the organic layer by thermal evaporation. This cathode showed high transmittance over 70% in visible range, and the device with a Ba-Ag has a low turn on voltage and good electrical properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.154-154
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• 2010

We have developed transparent OLED with green phosphorescent doped layer using transparent metal cathode deposited by thermal evaporation technique. Phosphorescent guest molecule, $Ir(ppy)_3$, was doped in host mCP for the green phosphorescent emission. Ca/Ag double layers were used as a cathode material of transparent OLED. The turn-on voltage of OLED was 5.2 V. The highest efficiency of the device reachs to 31 cd/A at 2 mA/$cm^2$.

• Transactions on Electrical and Electronic Materials
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• v.15 no.1
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• pp.45-48
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• 2014

We have investigated the effects of an Ag capping layer on the emission characteristics of transparent organic light-emitting devices with Ca/Ag double-layer cathodes. The thickness of the Ag layer was varied from 10 to 30 nm, whereas the Ca was fixed to be a 10 nm in the Ca/Ag structure. The luminance and current efficiency on the cathode and anode sides are significantly dependent on the Ag thickness. For example, the current efficiency on the anode side increases from 8.4 to 11.7 cd/A, whereas, on the cathode side, it decreases from 3.2 to 0.2 cd/A as the Ag thickness increases from 10 to 30 nm. These changes in emission characteristics were investigated by measuring electroluminescence, transmission, and reflection spectra.

• Korean Journal of Materials Research
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• v.30 no.8
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• pp.421-425
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• 2020

A transparent quantum dot (QD)-based light-emitting diode (LED) with silver nanowire (Ag NW) and indium-tin oxide (ITO) hybrid electrode is demonstrated. The device consists of an Ag NW-ITO hybrid cathode (-), zinc oxide, poly (9-vinylcarbazole) (PVK), CdSe/CdZnS QD, tungsten trioxide, and ITO anode (+). The device shows pure green-color emission peaking at 548 nm, with a narrow spectral half width of 43 nm. Devices with hybrid cathodes show better performances, including higher luminance with higher current density, and lower threshold voltage of 5 V, compared with the reference device with a pure Ag NW cathode. It is worth noting that our transparent device with hybrid cathode exhibits a lifetime 9,300 seconds longer than that of a device with Ag NW cathode. This is the reason that the ITO overlayer can protect against oxidization of Ag NW, and the Ag NW underlayer can reduce the junction resistance and spread the current efficiently. The hybrid cathode for our transparent QD LED can applicable to other quantum structure-based optical devices.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.990-993
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• 2006

We fabricated top emission organic light emitting diode (TEOLED) with transparent metal cathode Barium and Silver bilayer. Very thin Ba/Ag bilayer was deposited on the organic layer by thermal evaporation. This cathode shows high transmittance over 70% in visible range. And the device with a Ba-Ag has a low turn on voltage and good electrical properties.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.457-458
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• 2006

Transparent metal cathodes using Ca/Ag, Ba/Ag double layers have been fabricated to investigate its optical transmission. The transmission spectra show that Ca/Ag and Ba/Ag double layers result in higher transmittance compared to Ag single layer. The Ba/Ag double layer shows over 80% transmittance at 400 nm and 70% at 700 nm. The electroluminescence efficiency of fluorescent TEOLED using Ba/Ag transparent metal cathode was 10 ~ 15 cd/A.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.326-329
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• 2005

Proton exchange membrane (PEM) should be sufficiently hydrated with proper water management to maintain a good ionic conductivity and performance of a PEM fuel cell. However. cathode flooding resulting from excess water can impede the transport of reactants and hence deteriorate the fuel cell performance. For the PEM fuel cell to be commercially viable as vehicle or portable applications, the flooding on the cathode side should be minimized during the fuel cell operation. In this study, visualization technique was applied to understand the cathode flooding phenomena on the cathode side of a PEM fuel cell. To this end. a transparent PEM unit fuel cell wi th an act ive area of $25cm^2$ was designed and manufactured to allow for the visualization of cathode channel with performance characteristics. Two-phase flow resulting from the electro-chemical reaction of fuel cell was investigated experimentally. The images photographed by CCD camera with cell operating temperatures $(30\~50^{\circ}C)$ were presented. Results indicated that the flooding on the cathode side first occurs near the exit of cathode channel. As the operating temperature of fuel cell increases. it was found that liquid water droplets tend to evaporate easily and it can have an influence on lowering the flooding level. It is expected that this study can effectively contribute to the detailed researches on modeling water transport of an operating PEM fuel cell including two-phase flow phenomena.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.107-110
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• 2003

본 연구에서는 캐소드 방향으로 발광하는 Top emission 소자를 설계 제작하였다. 이를 위하여 반투명한 금속 박막을 제작하여 전기적 특성과 광학적 특성을 비교 평가하였다. 이를 바탕으로 제작한 Top emission 소자를 bottom emission 소자와 비교하였을 때 구동 전압은 다소 높았으며 색좌표 및 스펙트럼이 이동하였는데 이동 정도와 경향성은 파장에 따라 다르게 나타났다

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.482-485
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• 2009

We have fabricated transparent white organic light emitting diodes (WOLEDs) for lighting application. The structure property relationship of hybrid WOLEDs has been investigated and optimized devices showed high efficiency. Introduction of transparent cathode of LiF/Al/Ag into the hybrid WOLED led highly efficient WOLED with good transparency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.9
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• pp.802-807
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• 2007

We have developed red phosphorescent top emission organic light-emitting diodes with transparent metal cathodes deposited by using thermal evaporation technique. Phosphorescent guest molecule, BtpIr(acac), was doped in host CBP for the red phosphorescent emission, Ca/Ag, Ba/Ag, and Mg/Ag double layers were used as cathode materials of top emission devices, which were composed of glass/Ni/2TNATA(15 nm)/${\alpha}$-NPD(35 nm)/CBP:BtpIr(acac)(40 nm, 10%)/BCP(5 nm)/$Alq_3$(5 nm)/cathodes. The optical transparencies of these metal cathodes strongly depend on underlying Ca, Ba, and Mg layers. These layers also strongly affect the electrical conduction and emission properties of the red phosphorescent top emission devices.