Journal of the Korean Applied Science and Technology (한국응용과학기술학회지)

The Korean Society of Applied Science and Technology (한국응용과학기술학회)
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Effect of Changing the Thickness of Charge Control Layer on Performance of Green Phosphorescent Organic Light-Emitting Diodes

녹색 인광 유기발광다이오드에서 전하 조절층의 두께 변화가 성능에 미치는 효과에 대한 연구

  • 이동형 (홍익대학교 정보디스플레이공학과) ;
  • 이석재 (홍익대학교 정보디스플레이공학과) ;
  • 구자룡 (홍익대학교 정보디스플레이공학과) ;
  • 이호원 (홍익대학교 정보디스플레이공학과) ;
  • 이송은 (홍익대학교 정보디스플레이공학과) ;
  • 양형진 (홍익대학교 정보디스플레이공학과) ;
  • 박재훈 (한림대학교 전자공학과) ;
  • 김영관 (홍익대학교 정보디스플레이공학과)
  • Received : 2013.04.29
  • Accepted : 2013.06.29
  • Published : 2013.06.30
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Abstract

We investigated green phosphorescent organic light-emitting diodes (PHOLEDs) with charge control layer (CCL) to produce high efficiency. The CCL and host material which was 4,4,N,N'-dicarbazolebiphenyl (CBP) of bipolar property can control the carrier movement in emitting layer (EML). The performance improvement by the insertion of CCL was realized to the well confined exciton and the reduced triplet exciton quenching effect in EML. Five types of devices (Device A, B, C, D, and E) were fabricated following the thickness of CCL within EML. The properties of device D using optimized thickness of CCL showed external quantum efficiency of 16.22% and luminous efficiency of 55.76 cd/A, respectively.

본 연구에서는 전하 조절층을 이용하여 녹색 인광 유기발광다이오드의 효율의 향상을 나타냈다. 양극성의 4,4,N,N'-dicarbazolebiphenyl (CBP)를 호스트와 전하 조절층으로 사용하여 발광층 내에서 전하의 이동을 원활하게 할 수 있다. 게다가 전하 조절층의 삽입으로 엑시톤을 효과적으로 발광층 내에 제한하여, 삼중항-삼중항 소멸 현상을 억제할 수 있음을 확인하였다. 발광층의 전체 두께는 유지하고, 전하 조절층의 변화를 준 다섯 개의 소자를 제작하여 최적화된 전하 조절층의 두께를 이용한 Device D는 외부 양자 효율 16.22%와 휘도 효율 55.76 cd/A의 성능을 보였다.

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References

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