• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.698-701
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• 2007

A top emission organic light emitting diode comprising of a triple anode on polycarbonate $film/TNATA/NPB/Alq_3:C545T/cathodes$ has been fabricated. The triple layer structure of Cr/Al/Cr allowed for fabrication of a crack-free anode and provided better higher work function than ITO anode.The anode showed compatibility with flexible plastic substrate and no crack was formed during bending test while ITO anode showed crack.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.182-183
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• 2012

Organic light emitting diode (OLED) 나 organic photovoltaic device (OPV)와 같은 유기소자에 전극으로 쓰이고 있는 indium tin oxide (ITO) 박막의 품질을 향상시키기 위해 수소 및 산소의 가스량을 조절하면서 rf power를 이용하여 ITO 박막을 증착한 후 전기적, 광학적 특성을 관찰하여 보았다. 또한 ITO 박막의 대면적화 및 양산화를 위하여 Roll to Roll 장비를 적용하였다. 산소 분율 0.3%에서 두께 180 nm 와 면저항 21 ohm/sq.를 나타냈으며 수소 분율 0.8%에서 두께 180 nm, 면저항 22 ohm/sq.이 관찰되었다. 또한 산소 분율 0.3%로 고정한 후 수소 분율을 변화시키며 관찰한 결과 수소분율 0.3%에서 두께 180 nm, 면저항 19 ohm/sq.를 나타내었다.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.281-284
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• 2004

Photo-induced memory effect of an organic light-emitting diode(OLED) composed of a hydrazone-derivative(DBAH) dispersed in bis-phenol-A type polycarbonate polymer(PCA) in the presence of thio-Michler's ketone, was investigated by the measuring of the current density and luminance at the various conditions. After the light exposure, the current of the OLED was decreased approximately one order, and the luminance of the OLED also decresed. This memory effct was erasable by heating the OLED to the temperature higher than the glass transition temperature(Tg). As shown in this result, we found the memory effect was erased by heating and returned to its original state in the hole injecting layer(HIL) of the OLED. A series of these phenomena was suggested the possibility of the application to the imaging plate.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1440-1442
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• 2007

In this work, we have modeled and fabricated microcavity-enhanced OLED using the 1-dimensional distributed Bragg reflector model (DBR). Results show that simulated spectrum intensity of microcavity OLED increased more than 30% compared to the conventional OLED, by use of DBR with $TiO_2$ and $SiO_2$. Spectral change of green and blue emission was expected to give the deeper color. The experimental design and characterization as well as the matching with simulated properties were performed for microcavity OLED for actual application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.12
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• pp.1341-1346
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• 2004

The OLED research is gone for two directions. One is material development research, and another one is structural improvement part. All two are thing to heighten luminescence efficiency of OLED. n other to improve luminescence efficiency of OLED Electron - hole pairs must consist much more in the device Their profiles are sensitive to mobility velocity of electrons and holes. In this paper, we demonstrate the difference of velocity between hole and electron by experiments, and compare with a data of simulation and experiment changing hole carrier transport layer thickness, so we get the optimal we improve luminescence efficiency. We suggest improving the efficiency of OLEDS would be to balance the injection of electrons and holes into light emission layer of the device. And, we improve understanding of the various luminescence efficiency through experiments and numerical analysis of luminescence efficiency in variable hole carrier transport layer's thickness.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.595-596
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• 2006

The flexible organic thin film transistor (OTFT) array to use as a switching device for an organic light emitting diode (OLED) was designed and fabricated in the microcontact printing and low-temperature processes. The gate, source, and drain electrode patterns of OTFT were fabricated by microcontact printing which is high-resolution lithography technology using polydimethylsiloxane(PDMS) stamp. The OTFT array with dielectric layer and organic active semiconductor layers formed at room temperature or at a temperature tower than $40^{\circ}C$. The microcontact printing process using SAM(self-assembled monolayer) and PDMS stamp made it possible to fabricate OTFT arrays with channel lengths down to even nano size, and reduced the procedure by 10 steps compared with photolithography. Since the process was done in low temperature, there was no pattern transformation and bending problem appeared. It was possible to increase close packing of molecules by SAM, to improve electric field mobility, to decrease contact resistance, and to reduce threshold voltage by using a big dielecric.

• Economic and Environmental Geology
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• v.50 no.3
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• pp.251-256
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• 2017

This study presents measures to enhance the efficiency of Successive Alkalinity Producing Systems(SAPS), a natural biological purification method that prevents environmental pollution arising from the release of Acid Mine Drainage(AMD) from abandoned mines into rivers and groundwater. The treatment of AMD using SAPS is based on biological processing technology that mostly involves sulfate reducing bacteria(SRB). It has been proven effective in real-world applications, and has been employed in various projects on the purification of AMD. However, seasonal decrease in temperature leads to a deterioration in the efficiency of the process because sulfate-reducing activity is almost non-existent during cold winters and early spring even if SRB is able to survive. Against this backdrop, this study presents measures to enhance the activity of the SRB of the organic layer by integrating light emitting diode(LED)s in SAPS and to maintain the active temperature using LEDs in cold winters. Given that mine drainage facilities are located in areas where power cannot be easily supplied, solar cell modules are proposed as the main power source for LEDs. By conducting further research based on the present study, it will be possible to enhance the efficiency of AMD treatment under extreme cold weather using solar energy and LEDs, which will serve as an environmentally-friendly solution in line with the era of green growth.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.609-613
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• 2006

4-(Dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) derivatives were synthesized by Knoevenagel condensation. They are red-emitting materials for OLED (Organic Light-Emitting Diode) composed of electron donor of aminostyryl groups and electron acceptor of two cyano(nitrile)groups in a conjugated structure. The structural properties of reaction products were analyzed by FT-IR and $^1H-NMR$ spectroscopy. The thermal stabilities and reactivities were measured by melting points and yields. The UV-visible and PL properties can be determined by exitation and emission spectra, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.664-668
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• 2011

In this study, we have fabricated the red OLED (organic light emitting diode). The basic device structure is ITO/hole transporting layer, TPD(500 $\AA$)/red emitting layer, Alq3 doped with DCM2:rubrene(20 $\AA$)/electron transporting layer, Alq3(M) (500 $\AA$-M $\AA$)/LiF(15 $\AA$)/Al(1,000 $\AA$). The thickness of electron transporting layer(500 $\AA$-M $\AA$) changed 0, 20, 40, 60 $\AA$. Turn on voltage of the red OLED was 5 V, 6 V, 6.5 V and 7.5 V, respectively with electron transfer layer changed ratio. Luminance of red OLED was 4,504, 1,840, 1,490 and 1,130 cd/$m^2$, respectively. Optimized electron transfer layer position changed ratio of the red OLED was 0 $\AA$.

• Resources Recycling
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• v.21 no.3
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• pp.65-73
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• 2012

There are several kinds of displays such as liquid crystal display (LCD), cathode ray tube (CRT), plasma display panel(PDP), light emitting diode (LED), organic light emitting diode (OLED), etc. Nowadays, recycling technologies of waste displays have been widely studied from economy and efficiency points of view. In this paper, patents and literature on the recycling technologies of the waste displays have been comprehensively analyzed. The search was limited to the open patents of USA (US), European Union (EU), Japan (JP), and Korea (KR) and SCI journals published from 1980 to 2011. Patents and journals were systematically compiled and collected using key-words search and filtered by pre-set filtering criteria. The trends of the patents and journals were thus analyzed according to the years, countries, companies, and technologies.