대한전자공학회논문지SD (Journal of the Institute of Electronics Engineers of Korea SD)

대한전자공학회 (The Institute of Electronics and Information Engineers)
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초박막 CsF/Al 전극 두께에 따른 유기발광소자의 양자효율 개선

An Improvement of Quantum Efficiency of the Organic Light Emitting Diodes with variable Ultrathin CsF/Al

  • 노병규 (建國大學校 電子情報通信工學科) ;
  • 김중연 (建國大學校 電子情報通信工學科) ;
  • 오환술 (建國大學校 電子情報通信工學科)
  • Roh, Byeong-Gyu (Dept. of Electronics, Information & Communication Engineering Kon-Kuk University) ;
  • Kim, Jung-Yeoun (Dept. of Electronics, Information & Communication Engineering Kon-Kuk University) ;
  • Oh, Hwan-Sool (Dept. of Electronics, Information & Communication Engineering Kon-Kuk University)
  • 발행 : 2000.12.01
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초록

본 논문에서는 유리기판 위에 공액고분자 물질인 MEH-PPV를 스핀 코팅한 후 Al 전극 사이에 초박막의 CsF층을 진공증착으로 삽입한 유기발광소자를 제안하였다. 이러한 구조에서 CsF층은 음극을 통해 주입된 전자들이 원활히 발광층으로 전송되어 유기발광소자의 발광효율을 증대시켰다. 또한 CsF층의 두께변화를 $2{\AA},\;4{\AA},\;8{\AA},\;10{\AA},\;20{\AA},\;50{\AA},\;75{\AA}$으로 변화를 주어 전류- 전압- 발광 특성을 조사하였다. 그리고 CsF/Al와 CsF/Au 및 Cs/Au 전극을 각각 진공증착하여 비교하였다. CsF층 두께가 $4{\AA}$에서 양자효율이 0.6%로 최대값을 나타냈고 $8{\AA}$ 이상에선 효율이 감소하였지만 CsF층이 없는 순수한 Al전극층에서 효율이 0.01%인 것에 비해 높은 양자효율 값을 유지하였다.

In this paper, we propose the organic light-emitting devices with vacuum evaporated ultrathin CsF layer between the AI electrode and conjugated polymer MEH-PPV which was spin coated. In this structure, the CsF layer will be well transferred the electron injection from the electrode to the emission layer MEH-PPV. Finally this structure enhances the emission efficiency of the organic light-emitting device. And we measured the I-V-L properties with the split of CsF thickness into the $2{\AA},\;4{\AA},\;8{AA},\;10{\AA},\;20{\AA},\;50{\AA},\;75{AA}$ respectively. And also we evaporated CsF/Al, CsF/Au Cs/Au electrode respectively for the comparison. As the results, we obtained the maximum quantum efficiency 0.6% at $4{\AA}$ CsF thickness and then at $8{\AA}$, it decreased a little but it's still better than pure Al electrode which has 0.01%.

키워드

참고문헌

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