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Organic light-emitting diode (OLED) microdisplays have attracted considerable attention owing to their low power consumption, rapid response, high contrast ratio, and self-luminescence. To expand the use of OLED microdisplays, high luminance and vivid color are required. Herein, we developed a high-luminance, low-voltage, three-wavelength, top-emitting white OLED (WOLED) using a silicon substrate for complementary metal–oxide–semiconductor-based, full-color microdisplay applications. Optimal thickness of the emitting layer and thickness and position of the interlayer were determined to improve device performance. The device exhibited luminance of ∼4,200 cd/m2 at 3.3 V, and the maximum luminance reached 170,000 cd/m2 at 11.4 V. In addition, red, green, and blue color filters were deposited onto the WOLED after the thin-film encapsulation process to verify feasibility of the device for full-color microdisplay applications. The color gamut of the developed WOLED with color filters was 136% compared to sRGB. The maximum luminance and color gamut of the developed device is among the highest values obtained to date for OLED microdisplays.

We present herein the first report of organic/inorganic hybrid thin-film encapsulation (TFE) developed as an encapsulation process for mass production in the display industry. The proposed method was applied to fabricate a top-emitting organic light-emitting device (TEOLED). The organic/inorganic hybrid TFE has a 1.5 dyad structure and was fabricated using plasma-enhanced atomic layer deposition (PEALD) and inkjet printing (IJP) processes that can be applied to mass production operations in the industry. Currently, industries use inorganic thin films such as SiNx and SiOxNy fabricated through plasma-enhanced chemical vapor deposition (PECVD), which results in film thickness >1 μm; however, in the present work, an Al2O3 inorganic thin film with a thickness of 30 nm was successfully fabricated using ALD. Furthermore, to decouple the crack propagation between the adjacent Al2O3 thin films, an acrylate-based polymer layer was printed between these layers using IJP to finally obtain the 1.5 dyad hybrid TFE. The proposed method can be applied to optoelectronic devices with various form factors such as rollables and stretchable displays. The hybrid TFE developed in this study has a transmittance of 95% or more in the entire visible light region and a very low surface roughness of less than 1 nm. In addition, the measurement of water vapor transmission rate (WVTR) using commercial MOCON equipment yielded a value of 5 × 10-5 gm-2 day-1 (37.8 °C and 100% RH) or less, approaching the limit of the measuring equipment. The TFE was applied to TEOLEDs and the improvement in optical properties of the device was demonstrated. The OLED panel was manufactured and operated stably, showing excellent consistency even in the actual display manufacturing process. The panel operated normally even after 363 days in air. The proposed organic/inorganic hybrid encapsulant manufacturing process is applicable to the display industry and this study provides basic guidelines that can serve as a foothold for the development of various technologies in academia and industry alike.

Microdisplays based on organic light‐emitting diodes (OLEDs) have a small form factor, and this can be a great advantage when applied to augmented reality and virtual reality devices. In addition, a high‐resolution microdisplay of 3000 ppi or more can be achieved when applying a white OLED structure and a color filter. However, low luminance is the weakness of an OLED‐based microdisplay as compared with other microdisplay technologies. By applying a tandem structure consisting of two separate emission layers, the efficiency of the OLED device is increased, and higher luminance can be achieved. The efficiency and white spectrum of the OLED device are affected by the position of the emitting layer in the tandem structure and calculated via optical simulation. Each white OLED device with optimized efficiency is fabricated according to the position of the emitting layer, and red, green, and blue spectrum and efficiency are confirmed after passing through color filters. The optimized white OLED device with color filters reaches 97.8% of the National Television Standards Committee standard.

Organic light-emitting diode (OLED) microdisplays have attracted much attention as displays for small form factor augmented reality (AR) devices. To realize glass-like thin and wide field of view (FoV) AR devices, we designed a display module with a high aspect ratio microdisplay and a thin optical component. For the high aspect ratio microdisplay, we developed the color OLED microdisplay with a 32:9 aspect ratio and a 0.8-inch diagonal ∼2,490-ppi CMOS backplane. To express color and reduce optical crosstalk, we fabricated the color filter (C/F) patterning directly on the white OLED. We also developed a pin mirror lens with 11 pin mirrors to improve the optical efficiency and quality with a thin lens. By combining the microdisplay with LetinAR’s pin mirror lens, we successfully demonstrated an AR device with a wide horizontal FoV of 46° but with a small form factor 4 mm lens.

Colloidal quantum dots (QDs) stand at the forefront of a variety of photonic applications given their narrow spectral bandwidth and near-unity luminescence efficiency. Integrating desired forms of QD films into photonic systems without compromising their optical or transport characteristics is the key to bridging the gap between expectations and outcomes. Here, we devise a dual-ligand passivation system comprising photocrosslinkable ligands and dispersing ligands to enable QDs to be universally compatible with solution-based patterning techniques. The successful control on the structure of both ligands allows multiscale, direct patterning of the dual-ligand QDs on various substrates via commercialized photolithography (i-line) or inkjet printing systems without compromising the optical properties of QDs or the optoelectronic performances of the devices implementing them. Our approach offers a versatile way of creating various structures of luminescent QDs in a cost-effective and non-destructive manner, and thus enables the implementation of QDs in a range of photonic applications.

This article explores interpretive practices and discursive arguments that mediate transnational influences. In South Korea, a growth-oriented economy, competitive democracy, and an antagonistic relationship with North Korea developed during the Cold War era under the strong influence of the U.S. and Japan. This study analyzes how Germany—a country that is regarded as an exemplary case for a social market economy, consensus democracy, and successful national reunification—was imagined as a model for reform. By analyzing editorials and opinion articles published in major Korean newspapers, this article investigates the aspects of Germany that Korean elites paid attention to and the narratives that they constructed about Germany. The results show that competing Korean elites produced different German narratives and “German models,” leading to the integration of these competing models into conflicts surrounding South Korea’s future.

2019년의 ‘조국 사태’를 계기로 해서 ‘386 세대’에 대한 비판 담론이 언론매체에서 크게 확산되었다. 이 담론은 ‘386’이라는 집단범주에 한편으로는 ‘민주화,’ ‘진보,’ ‘평등,’ ‘정의’ 등의 가치 언어를, 다른 한편으로는 ‘기득권,’ ‘불평등,’ ‘위선,’ ‘이중성’ 등의 부정적 언어를 연결시킴으로써 특정한 사회적 의미구조를 응축하게 되었다. 이 연구는 ‘386 세대’ 담론이 처음 등장한 1990년대 이후 지난 30년 동안 이 담론이 과연 언제, 어떤 맥락에서, 어느 매체에서 가장 빈번히 생산되었으며, 이 담론의 상징과 의미구조가 어떤 특성과 변화 추이를 보여주는지를 분석했다. 결과는 다음과 같다. 첫째, 386 세대’ 담론의 출현 빈도는 2000년, 2010년, 2019년에 세 차례의 대(大)고조기와 밖에 몇 차례의 소(小)고조기를 보였으며, 그중 압도적 다수는 ≪조선일보≫, ≪중앙일보≫, ≪동아일보≫, ≪한겨레신문≫, ≪경향신문≫의 5개 매체에서 생산되었다.둘째, ‘386 세대’ 담론이 고조된 거의 모든 시기는 선거나 정당 일정에 따른 정치권 재편과 세력 갈등에 관련되었으나, 오직 2019년의 ‘조국 사태’ 때에만 정치권 재편과 무관하게 이 담론이 폭발했다. 셋째, 지난 30년 동안 대부분의 ‘386 세대’ 담론은 민주화 운동 출신 정치인 그룹에 대한 관심, 기대, 비판에 관련되었으나, 2019년에는 민주화와 평등, 정의 등 진보적 가치를 표방해 온 정치•사회 세력 전체를 위선적 기득권 집단으로 재현하는 새로운 담론유형이 확산되었다. 넷째, 그처럼 이념화된 세대 담론으로서의 ‘386’ 혐오 담론은 노무현 정부 시기에 보수 언론에서 탄생해 보수정권 시기 동안 복해 있다가 문재인 정부 등장 이후 다시 폭발했고 진보 매체에까지 확산되었다.

Thin-film transistor (TFT)-driven full-color organic light-emitting diodes (OLEDs) with vertically stacked structures are developed herein using photolithography processes, which allow for high-resolution displays of over 2,000 pixels per inch. Vertical stacking of OLEDs by the photolithography process is technically challenging, as OLEDs are vulnerable to moisture, oxygen, solutions for photolithography processes, and temperatures over 100 °C. In this study, we develop a low-temperature processed Al2O3/SiNx bilayered protection layer, which stably protects the OLEDs from photolithography process solutions, as well as from moisture and oxygen. As a result, transparent intermediate electrodes are patterned on top of the OLED elements without degrading the OLED, thereby enabling to fabricate the vertically stacked OLED. The aperture ratio of the full-color-driven OLED pixel is approximately twice as large as conventional sub-pixel structures, due to geometric advantage, despite the TFT integration. To the best of our knowledge, we first demonstrate the TFT-driven vertically stacked full-color OLED., To realize organic light-emitting diodes (OLEDs) with improved resolution for display applications, a method for achieving high yield device fabrication is needed. Here, the authors report vertically-stacked transistor-driven full-color OLEDs with photolithography-processed intermediate electrodes.

민주화 이후 국가에 대한 논의는 국가의 역할과 기능, 국가권력의 남용에 대한 견제라는 질문에 집중되어 있었다. 이 논문은 그와 같은 국가이상을 실현하기 위한 현실적 조건을 뜻하는 ‘국가역량’, 즉 국가의 조직, 재정, 인력, 지식, 정치적 능력으로 관심을 확장한다. 최근 국가역량, 정부역량, 거버넌스, 정부의 질 등에 관한 연구가 국내 · 외적으로 급증하고 있는 가운데, 이 논문은 기존 연구의 세 가지 문제점에 초점을 맞춰 대안을 모색한다. 그것은 첫째, 현실에서 떨어질 수 없는 국가의 목표 수립과 실행 능력을 분리시켜서 국가역량 개념을 정책실행 능력으로 협소화시키고, 둘째, 그 분석적 차원을 강압 · 행정 · 재정 능력으로 국한하며, 셋째, 국가역량의 다차원성을 간과한 채 각국의 국가가 강한가, 약한가만을 묻는 일차원적 문제틀을 갖고 있다는 점이다. 그러한 한계를 극복하기 위해, 이 논문은 국가역량 연구에 기초를 제공한 사회학의 주요 문헌들을 비판적으로 재구성하여 이 개념의 의미내용과 분석틀을 확장하고자 시도했다. 논문의 핵심 주장은 다음과 같다. 첫째, 국가역량은 공적 목표를 수립하고 이를 실행함으로써 영토 내 사회집단들의 행위와 관계를 제도적으로 규제하고 그에 영향을 미칠 수 있는 일체의 가능성을 포함한다. 둘째, 이처럼 확장된 개념 이해에 상응하여 국가역량의 분석적 차원은 강압 · 행정 · 조세와 같은 도구적 역량뿐 아니라, 현대의 민주적 자본주의 복지국가의 핵심적 활동인 법적 규제, 재분배적 개입, 경제활동 촉진의 역량을 포함해야 한다. 셋째, 다양한 차원의 국가역량은 종종 불균등하게 발전하고 심지어 상충하는 관계에 놓이기도 하기 때문에, 국가역량의 여러 부문 간의 특수한 배열과 결합 관계를 고찰하여 국가역량 레짐의 역사적 변화와 국가별 다양성을 규명함으로써 보다 정밀한 인식을 획득할 수 있다.

This chapter describes the developments and macrostructural changes of South Korean social movements after democratization in 1987. Several aspects will be highlighted: First, the developments in the number of civil society organizations, citizens’ participation in civil society activities, and non-violent protest culture have been accelerated since the 2000s. Second, the social movement sector has been differentiated into independent issue areas, leading to more diversity, but also to uneven development between movement areas. Third, with the rise of networked social movements, the communication and mobilization structures and the broader ecosystem of social movements have become increasingly decentralized. Fourth, not only has the ideological division between progressive and conservative movements intensified, but also radical right-wing movements are spreading. Fifth, most recently, a new generation of social movements representing the voices of women, youth, precarious workers, and local communities is growing quickly.

Due to the imperfections of top metal electrodes, top-emitting organic light emitting diodes (TEOLEDs) suffer low efficiencies and non-uniform angular emission spectral characteristics. We demonstrate a novel and simple method of overcoming these drawbacks by directly forming wrinkles on the thin film encapsulation (TFE) surface of TEOLEDs. The developed method relies on the use of a liquid prepolymer that spontaneously forms randomly distributed micron-sized wrinkles upon exposure to ultra-violet light. The wrinkles contribute to the extraction of light confined in the air mode by widening the angle of the escape cone, leading to a 1.4-fold increase in the current efficiency. Due to the spatial randomness of the organic wrinkle structure, almost negligible spectral angular dependency was achieved. As a merit of the simple process at room temperature without complicated processes such as patterning and vacuum processes, the developed organic wrinkle structure can be directly used to enhance the characteristics of TEOLEDs, and is expandable to flexible OLEDs and various optoelectronic devices.

From the very first time that graphene was used as a transparent electrode for OLED applications, the emergence of active-matrix (AM)-graphene OLED displays has been envisioned. Realizing this expectation, however, turned out to be difficult. Two obstacles are the growth and transfer of a large-area graphene film and the patterning of a graphene film into pixels. To solve these problems, a process of patterning a graphene film without surface contamination was developed. The fabrication of OLED panels by the patterned graphene anode on Gen 2(370 × 470 mm)-sized and flexible substrates was successfully demonstrated. In this work, oxide TFT arrays were combined as a switching backplane, and a pixelated graphene OLED was used as an emissive layer, to realize AM-graphene OLED displays. To explore the technical feasibility of flexible AM-graphene OLED displays, the aforementioned components were formed on a flexible substrate. For commercial-level production, all the processes that were used were chosen to be compatible with the conventional display processes.

Microdisplay is a key technology for realizing augmented reality (AR) and mixed reality (MR) devices, which have attracted much attention of late. Even though the operating voltage in the tandem structure is higher than that in the single structure, 2-stack tandem OLED exhibited 20,000 cd/m2 at 9 V, which is compatible with CMOS circuit driving. Due to its top-emitting geometry with a tandem structure, the OLED device with a well-controlled thickness exhibited a white spectrum with (0.26, 0.26) color coordinates. The pixel density of the fabricated microdisplay panel with a white tandem OLED was about 2350 pixels per inch, and the active area of the panel was 0.7 inch diagonally. The resolution of the panel was 1280 × 1024, corresponding to SXGA, and the maximal luminance was 3,000 cd/m2.