• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.1023-1026
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• 2007

Highly efficient inverted bottom emission organic light emitting device (IBOLED) with a structure of ITO/EIL/Alq3/NPB/WO3/Al was investigated. To enhance electron injection from ITO cathode to Alq3 EML layer, we introduced ultra thin Al layer and Liq layer between ITO and Alq3. The device characteristics showed tune on voltage of 4.5V, the maximum luminance of 21100 Cd/m2 and current efficiencies of 3.56 Cd/A.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08b
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• pp.1121-1124
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• 2007

Ink jet printing has been targeted as a key technology for OLED, TFT backplane and other organic semiconductor device fabrication. This presentation will concentrate on aspects of the IJ process, formulation design, jetting performance, interaction with the substrate and resultant printed device performance.

• Journal of the Semiconductor & Display Technology
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• v.5 no.4 s.17
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• pp.29-34
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• 2006

In order to design an OLED(Organic Luminescent Emitting Device) evaporation system, geometric simulation of film thickness distribution profile is required. For the OLED evaporation process, thin film thickness uniformity is of great practical importance. In this paper, a geometric modeling algorithm is introduced for process simulation of the OLED evaporating process. The physical fact of the evaporating process is modeled mathematically. Based on the developed method, the thickness of the thin-film layer can be successfully controlled.

• Journal of Information Display
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• v.5 no.1
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• pp.28-33
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• 2004

A high voltage NMOSFET is proposed to drive top emission organic light emitting device (OLED) used in the organic electroluminescent (EL) display on the single crystal silicon substrate. The high voltage NMOSFET can be fabricated by utilizing a simple layout technique with a standard CMOS logic process. It is clearly shown that the maximum supply voltage ($V_{DD}$) required for the pixel-driving transistor could reach 45 V through analytic and experimental methods. The high voltage NMOSFET was fabricated by using a standard 1.5 ${\mu}m$, 5 V CMOS logic process. From the measurements, we confirmed that the high voltage NMOSFET could sustain the excellent saturation characteristic up to 50 V without breakdown phenomena.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.4
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• pp.365-368
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• 2008

Feasibility test for radical reactions in organic light emitting diode(OLED) has been applied on OLED consisting of hole transport layer(HTL) and electron transport layer(ETL). Organic molecules such as 4,4',-Bis[N-(1-naphthyl)-N-phenylamino] biphenyl(NPD) and 4,4',4"-tris(3-methylphenylphenylamino)triphenylamine(m-MTDATA) are chosen for hole transport layer(HTL) and Bathocuproine(BCP) for electron transport layer(ETL) in this study. Informations on energy and shape of frontier orbitals and data on radical reactions of simple aromatics from semiconductor($TiO_2$) photocatalysis have provided basis for determining feasibility for radical reactions in OLED. The outcome of our feasibility test would be useful in designing optimum molecule for organic layer with a view to extending the lifetime of OLED.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.147-148
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• 2005

We report on high-performance organic field-effect transistors by promoting surface-mediated two-dimensional molecular ordering in organic semiconductor. To achieve this goal, we have controlled the intermolecular interaction at the interface between organic semiconductor and the insulator substrate.

• Journal of the Semiconductor & Display Technology
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• v.7 no.1
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• pp.35-40
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• 2008

In OLED vacuum evaporation process, the essential requirements include good uniformity of the film thickness over a glass substrate. And, it is commercially significant to improve the consuming efficiency of material of the evaporant which is deposited on the substrate because of high price of organic materials. In this paper, to achieve the better thickness uniformity and the better organic material consuming rate, a process optimization algorithm was developed by understanding vacuum evaporation process parameters that affect the material consuming efficiency and the uniformity of film thickness. Based on the method developed in this study, the vacuum evaporation process of OLED was successfully controlled. The developed method allowed the manufacture of high quality OLED displays with cheaper fabrication cost.

• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.23-27
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• 2010

We prepared Al doped ZnO thin film as a top electrode on a glass substrate with a deposited $Alq_3$ for the top emission organic Light emitting device (TEOLED) with facing target sputtering (FTS) method and radio-frequency (RF) sputtering method, respectively. Before the deposition of AZO thin film, we evaporated the $Alq_3$ on glass substrate by thermal evaporation. And we evaluated the damage of organic layer. As a result, PL intensity of $Alq_3$ on grown by FTS method showed higher than that of grown by RF sputtering method, so we found that the FTS showed the lower damage sputtering than RF sputtering. Therefore, we can expect the FTS method is promising the low-damage sputtering system that can be used as a direct sputtering on the organic layer.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.299-299
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• 2011

A dipolar interlayer can cause dramatic changes in the device characteristics of organic field-effect transistors (OFETs) or photovoltaics. A shift in the threshold voltage, for example, has been observed in an OFET where the organic semiconductor active layer is deposited on SiO2 modified with a dipolar monolayer. Dipolar molecules can similarly be used to change the current-voltage characteristics of organic-inorganic heterojunctions. We have conducted a series of experiments in which different molecular linkages are placed between a pentacene thin film and a silicon substrate. Interface modifications with different linkages allow us to predict and examine the nature of tunneling through pentacene on modified Si surfaces with different dipole moment. The molecular-scale structure and the tunneling properties of pentacene thin films on modified Si (001) with nitrobenzene and styrene were examined using scanning tunneling spectroscopy. Electronic interfaces using organic surface dipoles can be used to control the band lineups of a semiconductor at organic/inorganic interfaces. Our results can provide insights into the charge transport characteristics of organic thin films at electronic interfaces.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.119-124
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• 2022

Top emission organic light-emitting diode (TEOLED) is commonly used because of high efficiency and good color purity than bottom - emission organic light-emitting device (BEOLED). Unlike BEOLED, TEOLED contain semitransparent metal cathode and capping layer. Because there are many characteristics to consider just simple thickness change, optimizing organic thickness of TEOLED for microcavity is difficult. So, in this study, we optimized Device capping layer at unoptimized micro-cavity structure TEOLED device. And we compare only capping layer with unoptimized microcavity structure can overcome optimized micro-cavity structure device. We used previous our optimized micro-cavity structure to compare each other. As a result, it has been found that the efficiency can be obtained almost the same or higher only capping layer, which is stacked on top of the device and controls only the thickness and refractive index, without complicated structural calculations. This means that higher efficiencies can be obtained more easily in laboratories with limited organic materials or when optimizing new structures etc.