Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
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Structural and electrical characteristics of IZO thin films deposited on flexible substrate

유연 기판 위에 증착된 IZO 박막의 구조적 및 전기적 특성

  • Lee, B.K. (Dept. of Materials Engineering, Korea University of Technology and Education) ;
  • Lee, K.M. (Dept. of Materials Engineering, Korea University of Technology and Education)
  • 이봉근 (한국기술교육대학교 신소재공학과) ;
  • 이규만 (한국기술교육대학교 신소재공학과)
  • Received : 2011.05.05
  • Accepted : 2011.05.31
  • Published : 2011.06.30
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Abstract

In this study, we have investigated the structural and electrical characteristics of IZO thin films deposited on flexible substrate for the OLED (organic light emitting diodes) devices. For this purpose, PES was used for flexible substrate and IZO thin films were deposited by RF magnetron sputtering under oxygen ambient gases (Ar, $Ar+O_2$) at room temperature. In order to investigate the influences of the oxygen, the flow rate of oxygen in argon mixing gas has been changed from 0.1sccm to 0.5sccm. All the samples show amorphous structure regardless of flow rate. The electrical resistivity of IZO films increased with increasing flow rate of $O_2$ under $Ar+O_2$. All the films showed the average transmittance over 85% in the visible range. The OLED device was fabricated with different IZO electrodes made by configuration of IZO/a-NPD/DPVB/$Alq_3$/LiF/Al to elucidate the performance of IZO substrate. OLED devices with the amorphous-IZO (a-IZO) anode film show better current density-voltage-luminance characteristics than that of OLED devices with the commercial crystalline-ITO (c-ITO) anode film. It can be explained that very flat surface roughness and high work function of a-IZO anode film lead to more efficient hole injection by reduction of interface barrier height between anode and organic layers. This suggests that a-IZO film is a promising anode materials substituting conventional c-ITO anode in OLED devices.

Keywords

References

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