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Electrical Properties and Luminous Efficiency in Organic Light-Emitting Diodes Depending on Buffer Layer and Cathodes

버퍼층과 음전극에 따른 유기 발광 소자의 전기적 특성과 발광 효율

  • Published : 2003.05.01

Abstract

We have studied electrical properties and luminous efficiency of organic light-emitting diodes(OLEDs) with different buffer layer and cathodes in a temperature range of 10 K and 300 K. Four different device structures were made. The OLEDs are based on the molecular compounds, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) as a hole transport, tris(8-hydroxyquinolinato) aluminum(III) (Alq$_3$) as an electron transport and omissive layer, and poly(3,4-ethylenedioxythiophene) :poly (styrenesulfonate) (PEDOT:PSS ) as a buffer layer. And LiAl was used as a cathode. Among the devices, the ITO/PEDOT:PSS/TPD/Alq$_3$/LiAl structure has a low energy-barrier height for charge injection and show a good luminous efficiency. We have got a highly efficient and low-voltage operating device using the conductive PEDOT:PSS and low work-function LiAl. From current-voltage characteristics with temperature variation, conduction mechanisms are explained SCLC (space charge limited current) and tunneling one. We have also studied energy barrier height and luminous efficiency at various temperature.

Keywords

References

  1. Appl. Phys. Lett v.51 Organic electroluminscent diodes C.W.Tang;S.A.VanSlyke https://doi.org/10.1063/1.98799
  2. Solid State Communications v.102 Organic light emitting diodes Ananth Dodabalapur https://doi.org/10.1016/S0038-1098(96)00714-4
  3. 전기전자재료학회지 v.15 no.1 유기 발광 소자에서의 전기 전도 기구 정동희;김상걸;정택균;김태완;이준웅
  4. 전기전자재료학회지 v.12 no.6 유기 전기발광 소자의 구조 및 특성 하창식;임현택;정혜인;조원제
  5. 전기전자재료학회지 v.12 no.7 투명전도성 ITO 박막의 현황과 과제 신재혁;신성호;박정일
  6. J. Appl. Phys. v.75 no.3 Carrier tunneling and device characteristics in polymer light-emitting diodes I.D.Parker
  7. Organic Electronics v.2 Device physics of organic ligiht-emitting diodes based on molecular materials Wolfgang Brutting;Stafan Berleb;Anton G. Muckl https://doi.org/10.1016/S1566-1199(01)00009-X
  8. Proceeding of the KIEEME Annual Summer Conference 2002 v.3 no.1 Conduction mechanism in organic light-emitting diodes in ITO/PEDOT:PSS /TPD/Alq₃/LiAl structure D.H.Chung;S.K.Kim;T.G.Chung;H.S.Oh;W.J.Lee;J.W.Hong;J.U.Lee;T.W.Kim
  9. Proc. 2002 Summer Conf. KIEEME v.3 no.2 Efficiency improvement of OLEDs with a variation of cathodes S.K.Kim;D.H.Chung;T.G.Chung;H.S.Lee;K.U.Jang;M.G.Choi;J.W.Hong;J.U.Lee;T.W.Kim
  10. J. of Korean Oil Chemists' Soc. v.19 no.1 버퍼층으로 사용한 PVK의 농도 변화에 따른 유기 발광 소자의 전압-전류-휘도 특성 김상걸;홍진웅;김태완
  11. Synth. Met. v.91 Principles of material selection for thin-film organic light-emitting diodes Yakovlev;Yu.O;Zolin,V.F. https://doi.org/10.1016/S0379-6779(98)80032-5
  12. J. Appl. Phys. v.86 no.6 Charge carrier mobillty in electroluminescent alternatiog block copolymers Ma Dongge;I.A.Hummelgen https://doi.org/10.1063/1.371237
  13. Thin Solid Films v.363 Dependence of electro luminescent properties on cathode metals in PVCz double-layered organic EL devices Shnji Kawakami;Masahiko Kitagawa;Hiroyuki Kusano https://doi.org/10.1016/S0040-6090(99)00973-6
  14. Synthetic Metals v.111-112 The influence of oxyigen and air on the characteristics of organic light-emitting devices studied by in vacuo measurements J.Laubender;L.Chkoda;M.Sokolowski;E.Umbach https://doi.org/10.1016/S0379-6779(99)00331-8
  15. Ph.D.Thesis Efficiency Improvement and Electrical Properties of Organic Light-Emitting Diodes Sang-Keol Kim