Journal of the Korea Academia-Industrial cooperation Society (한국산학기술학회논문지)

The Korea Academia-Industrial cooperation Society (한국산학기술학회)
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Study on Color Shifting Mechanism for Organic Light Emitting Diode with Red Dopant-doped Emitting Layer

적색 도펀트가 도핑된 발광층을 갖는 유기발광다이오드에서의 컬러 시프트 메커니즘 연구

  • Lee, Ho-Nyeon (Dept. of Display and Electronic Information Engineering, Soonchunhyang University) ;
  • Oh, Tae-Sik (Dept. of Information Display, Sun Moon University)
  • 이호년 (순천향대학교 공과대학 전자정보공학과) ;
  • 오태식 (선문대학교 공과대학 정보디스플레이학과)
  • Received : 2011.07.27
  • Accepted : 2011.10.06
  • Published : 2011.10.31
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Abstract

The Color shift phenomenon is becoming a major degradation factor of the emitting color purity in the organic emitting diodes which is generating a plurality of colors. In this study, the basic structure of organic light emitting diode device is comprised of ITO/${\alpha}$-NPD/$Alq_3$:DCJTB[wt%]/$Alq_3$/Mg:Ag, we have carry out numerical simulation of the electric-optical characteristics in organic light emitting diode device to estimate the mechanism of color shift phenomenon. We have investigated the causes of the color shift through the change of DCJTB doping concentration ratio. As the result, we have confirmed that the changes of the recombination rate which generated by trapped electrons and holes is one of the major factors for the color shift phenomenon.

컬러 시프트 현상은 다양한 색상을 생성하는 유기발광다이오드 소자에 있어서 발광 색상의 순도를 저하시키는 주요 원인으로 작용되어지고 있다. 본 연구에 적용한 유기발광다이오드 소자의 기본 구조는 ITO/${\alpha}$-NPD/$Alq_3$:DCJTB [wt%]/$Alq_3$/Mg:Ag로 구성되어지며, 컬러 시프트가 일어나는 메커니즘을 규명하기 위하여 유기발광다이오드 소자 내에서의 전기광학적인 특성 요인들을 수치 해석하였다. 또한 DCJTB[wt%]의 도핑 농도 비율을 변화시켜 가면서 컬러 시프트의 원인을 조사하였다. 그 결과, 발광층과 정공 수송층의 경계면에서 발생되어지는 호스트에 트랩된 전자들과 자유 정공들 그리고 게스트에 트랩된 정공들과 자유 전자들에 의한 재결합율의 변화가 컬러 시프트 현상의 주요 요인들 중의 하나임을 확인하였다.

Keywords

References

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