Modifications of ITO Surfaces in Organic EL Devices by $O_2$ Plasma Treatment

O$_2$ 플라즈마 처리에 의한 ITO 표면개질 변화에 따른 유기 EL 소자 특성

  • 박상무 (인하대학 전기공학과) ;
  • 김형권 (한국소방검정공사) ;
  • 이덕출 (인하대학 전기공학과)
  • Published : 2003.06.01

Abstract

We investigated the effect of oxygen plasma treatment of indium-tin oxide(ITO) surface on the performance of electroluminescence(EL) devices. ITO surface treated oxygen plasma has been analyzed using atomic force microscope(AFM) and X-ray photoelectron spectroscopy(XPS), to investigate the relations between the properties of the ITO surface and the properties of the current-voltage-luminance(I-V-L) characteristics of the fabricated OLED with the structure of ITO(plasma treatment) / TPD / Alq$_3$/ Al. It is found that the oxygen plasma treatment of ITO anode improve the hole injection of the OLED due to the modification of the surface states. The treated ITO anode nay be low voltage with high luminance efficiency.

Keywords

oxygen plasma treatment;indium-tin oxide(ITO);electroluminescence(EL);OLED

References

  1. M. Ishii, T. Mori, H. Fujikawa, S. Tokito, Y. Taga, 'Improvement of organic electroluminescent device performance by in situ plasma treatment of indium-tin-oxide surface' J. Luminescence, Vol. 87-89, pp. 1165-1167, 2000 https://doi.org/10.1016/S0022-2313(99)00581-5
  2. J. R. Rasmusson, P. Broms, J. Birgersson, R. Erlandsson, and W. R. Salaneck, 'The interface surface of a CN- substituted poly(phenylenevinylene) light-emitting diode, a morphological study', Synth. Met, Vol. 79, pp. 75-78, 1996. https://doi.org/10.1016/0379-6779(96)80134-2
  3. W. R. Salaneck and J. L. Bredas, 'The metal-on-polymer interfaces in polymer light emitting diode', Adv. Mater, Vol. 9, pp. 48-51, 1996
  4. F. Steuber, J. Staudigel, M. Stossel, J. Simmerer, and A. Winnacker, 'Reduced operating voltage of organic electroluminescent devices by plasma treatment of the indium tin oxide anode,' Appl. Phys. Lett, Vol. 74, pp. 3558-3560, 1998 https://doi.org/10.1063/1.124160
  5. 이덕출, 임경범, 이백수, '플라즈마 표면처리에 따른 에폭시 복합재료의 표면특성', 전기전자재료학회지, Vol. 14, No. 10, pp. 821-827, 2001
  6. C. W. Tang, S. A. VanSlyke and C. H. Chen 'Electroluminescene of doped organic thin films', J. Appl. Phys., Vol. 65, pp. 3610-3616, 1989 https://doi.org/10.1063/1.343409
  7. 이덕출, 김형권, '디시아노메틸렌과 스쿠아리리움 색소 도핑 유기 LED의 전기 발광 기구 및 특성', 한국전기전자 재료 학회 , Vol. 12, No. 10, pp. 909-914, 1999
  8. 이덕출 외7, '버퍼층으로서 플라즈마 polythiophene이 유기EL소자에 미치는 영향',한국전기전자재료 학회, 춘계학술대회 논문집, pp. 177-180, 2002
  9. C. C. Wu, C. I. Wu, J. C. Sturm, and A. Kahn, 'Surface modification of indium tin oxide by plasma treatment: An effective method to improve the efficiency, brightness, and reliability of organic light emitting devices,' Appl. Phys. Lett, Vol. 70, pp. 1348-1350, 1997 https://doi.org/10.1063/1.118575
  10. C. W. Tang and S. A. VanSlyke, 'Organic electroluminescent diode', Appl. Phys. Lett, Vol. 51, pp. 913-915, 1987 https://doi.org/10.1063/1.98799