Article
  • Enhanced Efficiency of Organic Electroluminescence Diode Using 2-TNATA:C60 Hole Injection Layer
  • Park S, Kang DS, Park DW, Choe Y
  • 2-TNATA:C60 정공 주입층을 이용한 유기발광다이오드의 성능 향상 연구
  • 박소현, 강도순, 박대원, 최영선
Abstract
Vacuum deposited 4,4′,4″-tris(N-(2-naphthyl)-N-phenylamino)-triphenylamine (2-TNATA), used as a hole injection (HIL) material in OLEDs, is placed as a thin interlayer between indium tin oxide(ITO) electrode and a hole transporting layer (HTL) in the devices. C60-doped 2-TNATA:C60 (20 wt%) film was formed via co-evaporation process and molecular ordering and topology of 2-TNATA:C60 films were investigated using XRD and AFM. The J-V, L-V and current efficiency of multi-layered devices were characterized as well. Vacuum-deposited C60 film was molecularly oriented, but neither was 2-TNATA:C60 film due to the uniform dispersion of C60 molecules in the film. By using C60-doped 2-TNATA:C60 film as a HIL, the current density and luminance of a multi-layered ITO/2-TNATA:C60/NPD/Alq3/LiF/Al device were significantly increased and the current efficiency of the device was increased from 4.7 to 6.7 cd/A in the present study.

유기발광소자(OLED)에서 정공 주입층으로 사용되는 4,4′,4″-tris(N-(2-naphthyl)-N-phenylamino)-triphenylamine(2-TNATA)가 전극으로 사용되는 ITO(indium tin oxide)와 홀 수송층(hole transport layer, HTL)사이에 박막으로 진공 증착되었다. 공증착에 의해 C60이 약 20 wt% 도핑된 2-TNATA:C60 층을 제조하였으며, AFM과 XRD를 이용하여 2-TNATA:C60 박막의 분자 배향성 및 토폴로지를 관찰하였다. 또한, 다층 소자의 J-V, L-V 및 전류 효율 특성이 고찰되었다. C60은 분자 배향성을 가지고 있으나, 2-TNATA:C60 박막은 C60 분자의 균일한 분산에 의해 분자 배향성이 확인되지 않았다. C60의 도핑에 의해서 2-TNATA 박막이 더욱 조밀해지고 균일해지는 것을 확인하였으며, 이로 인하여 박막 내의 전류 밀도가 증가됨을 확인하였다. 2-TNATA:C60 하이브리드 박막을 이용하여 ITO/2-TNATA:C60/NPD/Alq3/LiF/Al 다층 소자를 제조하였을 때 소자의 휘도가 향상 되었으며 소자 효율도 약 4.7에서 약 6.7 cd/A로 증가하였다.

Keywords: 2-TNATA; OLED; C60 doping; current efficiency; vacuum deposition

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  • Polymer(Korea) 폴리머
  • Frequency : Bimonthly(odd)
    ISSN 0379-153X(Print)
    ISSN 2234-8077(Online)
    Abbr. Polym. Korea
  • 2022 Impact Factor : 0.4
  • Indexed in SCIE

This Article

  • 2008; 32(4): 372-376

    Published online Jul 25, 2008

  • Received on Mar 6, 2008
  • Accepted on May 17, 2008