Journal of IKEEE (전기전자학회논문지)

Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
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Solution Processed Hexaazatrinaphthylene derivatives as a efficient hole injection layer for phosphorescent organic light-emitting diodes

신규 용액공정 정공주입층 소재 Hexaazatrinaphthylene 유도체를 도입한 인광 유기전기발광소자

  • Lee, Jangwon (Department of Creative Convergence Engineering, Hanbat National University) ;
  • Sung, Baeksang (Department of Creative Convergence Engineering, Hanbat National University) ;
  • Lee, Seung-Hoon (Department of Creative Convergence Engineering, Hanbat National University) ;
  • Yoo, Jae-Min (Department of Creative Convergence Engineering, Hanbat National University) ;
  • Lee, Jae-Hyun (Department of Creative Convergence Engineering, Hanbat National University) ;
  • Lee, Jonghee (Department of Creative Convergence Engineering, Hanbat National University)
  • Received : 2020.07.14
  • Accepted : 2020.09.17
  • Published : 2020.09.30
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Abstract

To improve light-emitting performance of green phosphorescent organic light-emitting diodes (OLEDs), we introduced new hole injection materials-hexaazatrinaphthylene (HATNA) derivatives as a solution processed hole injection layer (HIL). The HATNA derivative has a low the lowest unoccupied molecular orbital (LUMO) energy level, similar to the work function of Indium Tin Oxide (ITO), showing a different concept of hole injection mechanism. It was confirmed that the device efficiency of OLEDs using HATNA-HIL showed the improved external quantum efficiency from 10.8% to 15.6% and current efficiency from 32.7 cd/A to 42.7 cd/A due to the balance of electrons and holes in the emissive layer.

유기전기발광소자(Organic light diodes, OLEDs)의 전기발광특성을 향상시키기 위해, 본 논문에서는 용액 공정 정공주입층으로 신규 hexaazatrinaphthylene(HATNA) 유도체들을 도입한 고효율 녹색인광 OLED소자의 특성을 연구하였다. HATNA 유도체는 Indium Tin Oxide(ITO)의 일함수와 비슷한 낮은 the lowest unoccupied molecular orbital(LUMO) 에너지 준위를 가져 다른 개념의 정공주입 메커니즘을 보여주었다. HATNA 유도체를 hole injection layer(HIL)로 사용한 OLED소자들은 HTL로의 정공주입장벽을 효과적으로 감소시키고 발광층 내에 전자와 정공의 균형을 최적화 시켜 외부양자효율이 10.8%에서 15.6%로, 전류 효율은 34.3 cd/A에서 42.7 cd/A로 소자 효율이 크게 향상 되었다.

Keywords

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