• 제목/요약/키워드: Light-emitting diodes

검색결과 1,318건 처리시간 0.037초

박스 캐소드 스퍼터로 성장시킨 전면 발광 OLED용 상부 InZnO 캐소드 박막의 전기적, 광학적, 구조적 특성 연구 (Electrical, Optical and Structural Properties of Indium Zinc Oxide Top Cathode Grown by Box Cathode Sputtering for Top-emitting OLEDs)

  • 배정혁;문종민;김한기
    • 한국전기전자재료학회논문지
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    • 제19권5호
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    • pp.442-449
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    • 2006
  • Electrical, optical, and structural properties of indium zinc oxide (IZO) films grown by a box cathode sputtering (BCS) were investigated as a function of oxygen flow ratio. A sheet resistance of $42.6{\Omega}/{\Box}$, average transmittance above 88% in visible range, and root mean spare roughness of $2.7{\AA}$ were obtained even in the IZO layers grown at room temperature. In addition, it is shown that electrical characteristics of the top-emitting organic light emitting diodes (TOLEDs) with the BCS grown-IZO top cathode layer is better than that of TOLEDs with DC sputter grown IZO top cathode, due to absence of plasma damage effect. Furthermore the effects of oxygen flow ratio in IZO films are investigated, based on x-ray photoelectron spectroscopy (XPS), ultra violet/visible (UV/VIS) spectro-meter, scanning electron microscopy (SEM), and atomic force microscopy (AFM) analysis results.

표면 roughening을 통한 수직형 LED의 광 추출 효율 향상 (Effects of surface roughening on the light extraction efficiency of vertical light-emitting diodes)

  • 김태형;배정운;염근영
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2011년도 춘계학술대회 및 Fine pattern PCB 표면 처리 기술 워크샵
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    • pp.130-130
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    • 2011
  • vertical light-emitting diodes의 표면을 건식과 습식 두 가지 공정을 통해 식각하여 roughening을 주었고, 또한 이 고정으로 인해 표면이 전체적으로 거칠기를 가지므로써 외부 양자 효율의 증가를 기대하였다.

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OLED용 지연형광 소재의 연구 동향 (Research Trends of Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes)

  • 이주영
    • 세라미스트
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    • 제22권3호
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    • pp.218-229
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    • 2019
  • The development of highly efficient thermally activated delayed fluorescence (TADF) materials is an active area of recent research in organic light emitting diodes (OLEDs) since the first report by Chihaya Adachi in 2011. Traditional fluorescent materials can harvest only singlet excitons, leading to the theoretically highest external quantum efficiency (EQE) of 5% with considering about 20% light out-coupling efficiency in the device. On the other hand, TADF materials can harvest both singlet and triplet excitons through reverse intersystem crossing (RISC) from triplet to singlet excited states. It could provide 100% internal quantum efficiencies (IQE), resulting in comparable high EQE to traditional rare-metal complexes (phosphorescent materials). Thanks to a lot of efforts in this field, many highly efficient TADF materials have been developed. This review focused on recent molecular design concept and optoelectronic properties of TADF materials for high efficiency and long lifetime OLED application.

Deep red electrophosphorescent organic light-emitting diodes based on new iridium complexes

  • Gong, Doo-Won;Kim, Jun-Ho;Lee, Kum-Hee;Yoon, Seung-Soo;Kim, Young-Kwan
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1075-1078
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    • 2006
  • New iridium complex was synthesized and demonstrated a deep red light emission in organic light-emitting diodes (OLEDs). The maximum luminance of 8320 cd/m2 at 15 V and the luminance efficiency of 2.5 cd/A at 20 mA/cm2 were achieved. The peak wavelength of the electroluminescence was at 626 nm with the CIE coordinates of (0.69, 0.30), and the device also showed a stable color chromaticity with various voltages.

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SiNx 박막에 의한 OLED 소자의 보호막 특성 (Passivation Properties of SiNx Thin Film for OLEO Device)

  • 주성후
    • 한국전기전자재료학회논문지
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    • 제19권8호
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    • pp.758-763
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    • 2006
  • We has been studied the thin film encapsulation effect for organic light-emitting diodes (OLED). To evaluate the passivation properties of the passivation layer materials, we have carried out the fabrication of green light emitting diodes with ultra violet(UV) light absorbing polymer resin, $SiO_2,\;and\;SiN_x$, respectively. From the measurement results of shrinkage properties according to the exposure time to the atmosphere, we found that $SiN_x$ thin film is the best material for passivation layer. We have investigated the emission efficiency and life time of OLED device using the package structure of $OLED/SiN_x/polymer$ resin/Al/polymer resin. The emission efficiency of this OLED device was 13 lm/W and life time was about 2,000 hours, which reach 95 % of the performance for the OLED encapsulated with metal.