• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.416-417
• /
• 2007

We prepared flexible transparent conducting electrodes by spray coating of single-walled carbon nanotube (SWNT) networks on PET substrate and have demonstrated their use as transparent anodes for flexible organic light emitting diodes (OLEDs). The flexible CNT electrode produced by spray coating method shows relatively low sheet resistance ($150{\sim}220{\Omega}/sq.$) and high transmittance of ~60% even though it was prepared at room temperature. In addition, CNT electrode/PET sample exhibits little resistance change during 2000 bending cycles, demonstrated good mechanical robustness. Using transparent CNT electrode, it is readily possible to achieve performances comparable to commercial ITO-based OLEDs. This indicates that flexible CNT electrode is alternative anode materials for conventional ITO anode in flexible OLEDs.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2006.04a
• /
• pp.24-24
• /
• 2006

• Journal of Information Display
• /
• v.7 no.3
• /
• pp.23-26
• /
• 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 Surface Engineering Conference
• /
• 2017.05a
• /
• pp.161.1-161.1
• /
• 2017

최근 OLED기술을 조명에 응용하고자 하는 연구가 급증되고 있다. 이는 유연하고, 대면적 확장이 가능하며, 다양한 형태 구현에 있어 장점이 존재하기에 차세대 감성조명으로써 주목을 받고 있다. 고효율의 OLED 조명을 위해서는 저저항/고유연의 투명전극 소재의 개발을 통해 전기적 손실을 최소화해야하고, 광추출층의 적용을 통해 내부에서 생성된 빛을 외부로 잘 방출시켜 광학적 손실을 최소화해야한다. 이를 위해 많은 다양한 투명전극에 대한 연구와 광추출을 위한 방법에 대한 연구가 진행이 되고 있고, 두 가지 효과를 한번에 얻을 수 있는 집적기판에 대한 수요가 높아지고 있다. 본 연구는 인쇄공정과 플라즈마 공정을 통해, 미세배선이 함몰된 집적 기판을 개발하여 저저항/고유연 투명전극을 구현하였고 기판상 나노구조체 형성을 통해 광추출 효율을 기존에 비해 20% 이상 향상시킬 수 있었다. 이러한 기판은 향후 대면적 OLED 조명에 응용이 가능할 것이라 전망한다.

• Vacuum Magazine
• /
• v.1 no.2
• /
• pp.19-23
• /
• 2014

Transparent and top emission organic light-emitting device (OLEDs) are the important issues in realizing new display applications such as see-through electronic displays, and flexible displays. The cathode of the transparent and top emission OLEDs should be transparent in the visible light and should not give any damage to the underlying organic layers, in addition to its intrinsic role of injecting electrons into the organic layers. Several authors have investigated the transparent conducting oxide films prepared by sputtering methods. They have introduced the sophisticated sputtering process for reducing the damages. Other groups have developed thermally evaporated transparent cathodes which are believed to be damage free without causing any permanent defect to the organic layers. This review focuses on the vacuum evaporated damage free transparent cathodes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.4
• /
• pp.357-362
• /
• 2007

AZO(Aluminum-doped Zinc Oxide) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with ITO(Indium Tin Oxide). AZO films have been deposited on glass (corning 1737) substrates by RF magnetron sputtering. The AZO film was post-annealed at $600^{\circ}C$ for 2 hr with $N_2$ atmosphere. The AZO films were used as an anode contact to fabricate OLEDs(Organic Light Emitting Diodes). OLEDs with $AZO/TPD/Alq_3/Al$ configuration were fabricated by thermal evaporation. We investigated that the electric, structural and optical properties of AZO thin films, which measured using the methods of XRD, SEM, Hall measurement and Spectrophotometer. The current density-voltage and luminescence-voltage properties of devices were studied and compared with ITO devices fabricated under the same conditions.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.11B
• /
• pp.1403-1412
• /
• 2011

This study performed a detecting research of promising R&D field utilizing intuitive methodology regarding OLED illumination industry. For this, 69 professionals of the illumination industry in Korea were composed as a panel to hold an in-depth interview and survey for 1 month. The study classified the OLED illumination industry as 4 fields of panel, material/component for panel, manufacturing equipment, and lighting system, and selected core technology for each field, and divided it into a total of 14 possible fields for R&D. As a result of evaluating the technological competitive power for each field, the field in Korea which received the highest technological competitive power was OLED panel, and contrarily, technological competitive power of material/component for OLED panel showed the lowest, which requires improvement Meanwhile, evaluating economical aspect, conformity to policy, and effectiveness of R&D in general, 7 promising R&D fields were selected. The 4 core technologies of OLED panel, which are, white, transparent, color change and flexible OLED manufacturing technology were evaluated as the most promising fields, and next, organic material for surface light source, material/component for substrate and equipment for forming large sized substrate were evaluated as promising fields.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.91-92
• /
• 2006

Aluminum-doped zinc oxide (AZO) films are attractive materials as transparent conductive electrode because they are inexpensive, nontoxic and abundant element compared with indium tin oxide (ITO). AZO films have been deposited on glass (corning 1737) substrates by RF magnetron sputtering system. The electrical resistivity of AZO films was $1.81{\times}10^{-2}{\Omega}cm$ and the average transmittance in the visible range 400-800 nm was more than 76% Organic light-emitting diodes (OLEDs) with AZO/TPD/$Alq_3$/Al configuration were fabricated. The current density-voltage properties of devices were studied and compared with ITO devices fabricated under the same conditions.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.614-615
• /
• 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 Semiconductor & Display Technology
• /
• v.23 no.2
• /
• pp.82-86
• /
• 2024

With the growing field and growing interest in transparent organic light-emitting diodes (TOLED) in the industry, various attempts are being made to improve the transmittance and performance of TOLED. TOLEDs are expected to be used in next-generation displays such as mixture reality (MR) displays, displayable windows, televisions, etc. This study presents a mesh TOLED with better transmittance and luminescence characteristics than existing TOLEDs through an in-situ vacuum deposition method that does not require additional processes such as photolithography and etching. In this study the mesh TOLED's cathode consists of Mg: Ag 1:9 electrode. Mesh patterns are interconnected with a 6 nm layer of interlayer. We approached transmittance improvement up to 30% at 555 nm at the cathode electrode with similar current injection character, also we improved lumination characteristics up to 23% at 7 V driving condition.