• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.66-69
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• 2007

We have investigated printing techniques for processing organic light-emitting diodes (OLEDs). We succeeded to gravure print uniform organic thin films as well as screen print low work function cathode for OLED structure. Furthermore, by using roll-to-roll manufacturing methods, we have been able to fabricate all-printed flexible OLED demonstrator.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.448-448
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• 2007

OLED has many advantages of low voltage operation, self radiation, light weight, thin thickness, wide view angle and fast response time to overcome existing liquid crystal display (LCD)'s weakness. Therefore, It draws attention as promising display and has already developed for manufactured goods. Also, OLED is regarded as a only substitute of flexible display with a thin display. However, Indium tin oxide(ITO) thin film for electrode of OLED shows a low electrical properties and is impossible to deposit at high thermal condition because electrical characteristics of ITO is getting worse. One of the ways to realize an improved flexible OLED is to use high internal efficiency electrodes, which have higher work function than those single layer of ITO films of the same thickness. The high internal efficiency electrodes film is developed with structure of nickel oxide for bottom Emission Type of OLED.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.491-492
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• 2006

We report on the fabrication of organic-based flexible display using an amorphous IZO anode grown at room temperature. The IZO anode films were grown by a conventional DC reactive sputtering on polycarbonate (PC) substrate at room temperature using a synthesized IZO target in a Ar/$O_2$ ambient. X-ray diffraction examination results show that the IZO anode film grown at room temperature is complete amorphous structure due to low substrate temperature. It is shown that the $Ir(ppy)_3$ doped flexible organic light emitting diode (OLED) fabricated on the IZO anode exhibit comparable current-voltage-luminance characteristics to OLED fabricated on conventional ITO/glass substrate. These findings indicate that the IZO anode film grown on PC substrate is a promising anode materials for the fabrication of organic based flexible displays.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.574-581
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• 2012

The relatively short lifetime is a major obstruction for the commercial applications of OLED. One of the reason for the short lifetime is that the organic materials are interacted with water or oxygen in the atmosphere. Protection of water or oxygen from diffusing into the organic material layers are necessary to increase the lifetime of OLED. Although encapsulation of OLED with glass or metal cans has been established, passivation methods of OLED by organic/inorganic thin films are still being developed. In this paper we have developed in-situ passivation system and thin film passivation method using PECVD by which deposition can be performed at room temperature. We have analyzed the characteristics of the passivated OLED device also. The WVTR (Water Vapor Transmission Rate) for the inorganic thin film mono-layer can be reached down to $1{\times}10^{-2}g/m^2{\cdot}day$ and improved lifetime can be obtained. Thin film passivation methods are expected to be applied to flexible display.

• Information Display
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• v.9 no.5
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• pp.3-9
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• 2008

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.616-619
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• 2005

OLED display are extremely sensitive to water and oxygen. Developing a thin film encapsulation for this technology has for a long time been elusive. Vitex has developed a multilayer barrier consisting of alternating inorganic and organic layers which can meet the requirements for a successful protection for such displays. In this paper we will discuss the basic process, the model, the results on top and bottom emission OLED displays as well as the application of Barix layers on plastic to create flexible OLED displays. We will show that for displays all the requirement for the telecommunication industry can be met and that the we can scale up to a mass manufacturing process.

• Vacuum Magazine
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• v.1 no.2
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• pp.24-29
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• 2014

Display is a key component in electronic devices. OLED is growing very fast recently due to the explosion of the smart phone market although still LCD is the dominating display technology in the display market at the moment. Also needs for the large area and high resolution TVs and flexible displays are increasing these days. Especially flexible display is expected to be one of the key technologies in mobile devices requiring small device size and large display size. Contrary to the conventional displays, flexible display requires organic materials for the substrate, the active driving element and also for the display element. Plastic film as a substrate, organic semiconductor as an active component of the transistor and organic light emitting materials or electronic paper as a display element are studied actively. In this article, mainly backplane technologies such as substrates and the transistor materials for flexible display will be introduced.

• Journal of the Semiconductor & Display Technology
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• v.4 no.2 s.11
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• pp.15-19
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• 2005

The organic light-emitting devices(OLEDs) based on fluorescence have low efficiency due to the requirement of spin-symmetry conservation. By using the phosphorescent material, the internal quantum efficiency can reach 100$\%$, compared to 25$\%$ in case of the fluorescent material [1]. Thus recently phosphorescent OLEDs have been extensively studied and showed higher internal quantum efficiency than conventional OLEDs. In this study, we have applied a new Ir complex as a red dopant and fabricated a red phosphorescent OLED on a flexible PC(Polycarbonate) substrate. Also, we have investigated the electrical and optical properties of the devices with a structure of A1/LiF/Alq3/(RD05 doped)BAlq/NPB/2-TNAIA/ITO/PC substrate. Our device showed the lightening efficiency of > 30 cd/A at an initial brightness of 1000 cd/$m^{2}$. The CIE(Commission Internationale de L'Eclairage) coordinates for the device were (0.62,0.37) at a current density of 1 mA/$cm^{2}$. In addition, although the sheet resistance of ITO films on PC substrate is higher than that on glass substrate, the flexible OLED showed much better lightening efficiency without much increase in operating voltage.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.614-615
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• 2005

The use of plastic substrates enables new applications, such as flexible display devices, and other flexible electronic devices, using low cost, roll-to-roll (R2R) fabrication technologies. One of the limitations of polymeric substrate in these applications is that oxygen and moisture rapidly diffuse through the material and subsequently degrade the electro-optical devices. GE Global Research (GEGR) has developed a plastic substrate technology comprised of a superior high-heat polycarbonate ($LEXAN^{(R)}$) substrate film and a unique transparent coating package that provides the ultrahigh barrier (UHB) to moisture and oxygen,chemical resistance to solvents used in device fabrications, and a high performance transparent conductor. This article describes the coating solutions for polycarbonate ($LEXAN^{(R)}$) films and its compatibility with OLED device fabrication processes.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.1
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• pp.105-112
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• 2023

We analyze the global market for flexible electronic circuits, technical considerations, and analyze the market for application areas and regions. In the market analysis of the application field, the display field has the greatest influence in terms of market size and annual growth rate, and the OLE D lighting market size is expected to grow by nearly 50% in 2026. The multilayer flexible electronics, which dependently requires the semiconductor technology, has a larger market size than other structures and its growth rate is relatively large, leading the market and will be further analyzed in depth. The market size of multilayer flexible electronics applied to display field is expected to show an annual growth rate of 21.1% from $2.7 billion in 2017 to $9.8 billion in 2026, and the OLED market is expected to grow by 75.2% during the same periods. Recently, as electronic products have been miniaturized and advanced, and robust installation in a small space is required, companies that preoccupy multilayer structure or rigid flexible electronic circuit technology have an advantage in competitiveness, so many companies are trying to obtain this technology. These efforts are systematically supported by many countries because they can achieve mutual growth by strengthening the competitiveness of the application field and the same industry. In the case of Korea, a support system is established, but it is required to expand and activate it, and to localize manufacturing equipment and materials.