Korean Chemical Engineering Research

The Korean Institute of Chemical Engineers (한국화학공학회)
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Study on Electroluminescence of the Phosphorescent Iridium(III) Complex Prepared by Ultrasonic Wave

초음파 합성법을 이용한 이리듐계 인광 물질 합성과 합성된 인광 물질의 전계 발광 특성 분석

  • Yu, Hong-Jeong (Department of Chemical and Biological Engineering, Korea University) ;
  • Chung, Won-Keun (Department of Chemical and Biological Engineering, Korea University) ;
  • Chun, Byung-Hee (Department of Chemical and Biological Engineering, Korea University) ;
  • Kim, Sung-Hyun (Department of Chemical and Biological Engineering, Korea University)
  • 유홍정 (고려대학교 화공생명공학과 청정에너지 소재 연구실) ;
  • 정원근 (고려대학교 화공생명공학과 청정에너지 소재 연구실) ;
  • 전병희 (고려대학교 화공생명공학과 청정에너지 소재 연구실) ;
  • 김성현 (고려대학교 화공생명공학과 청정에너지 소재 연구실)
  • Published : 2011.06.30
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Abstract

$Ir(pmb)_{3}$(Iridium(III)Tri(1-phenyl-3-methylbenzimidazolin-2-ylidene-$C,C^{2'}$ ) was synthesized to develop a deep blue-emitting Ir(III) complex. We suggested the ultrasonic reactor to enhance the poor reaction yield of $Ir(pmb)_{3}$. The ultrasonic wave enhanced the reaction yield of $Ir(pmb)_{3}$ because the ultrasound helped non-soluble reactants disperse efficiently and produced free radial during the reaction. The maximum yield of $Ir(pmb)_{3}$ was 42.5%, which was 4 times higher than conventional method. Organic light emitting devices were fabricated with the synthesized mer-$Ir(pmb)_{3}$ which emitted at 405 nm. A range of host materials with large bandgaps (UGH2, mCP and CBP) were tested for developing a deep blue emitting device. In case of the device with mCP as the host material, it emitted deep blue and performed quite well relative to the other host materials tested.

본 연구를 통해 최근 개발된 근자외선영역대에서 발광하는 이리듐 착물인 $Ir(pmb)_{3}$ (Iridium(III) Tris(1-phenyl-3-methylbenzimidazolin-2-ylidene-C,$C,C^{2'}$ ))의 합성 과정상에서 기존의 합성법과 동일한 발광 특성을 가지면서 더 효율적인 합성 방법을 제안하였다. 합성 과정에서 초음파가 투입되면서 용매에 녹지 않는 반응물의 파쇄 및 혼합을 돕고, 촉매의 활성을 향상시켜 이온 및 라디컬을 형성시키는 방법으로 최대 42.5% 합성 수율을 얻어 내었으며 이는 기존 방법 대비 약 4배 이상 향상된 결과이다. 이러한 초음파 합성법으로 합성된 $Ir(pmb)_{3}$은 이성질체 별로 405 nm(면이성질체) 412 nm(자오선이성질체)의 발광 피크를 보였으며 이중 좀더 효율이 높은 자오선이성질체를 사용하여 전계 발광 소자를 제작하였다. 밴드갭이 큰 $Ir(pmb)_{3}$에 적합한 호스트 물질을 UGH2, CBP, mCP 세가지 선정하여 전계발광소자를 제작하였으며, 그 중 mCP를 호스트 물질로 사용한 소자의 경우가 호스트물질과 인광물질사이의 에너지전달이 가장 효율적으로 일어나 가장 높은 휘도와 효율을 보였다.

Keywords

References

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