Journal of Adhesion and Interface (접착 및 계면)

The Society of Adhesion and Interface, Korea (한국접착및계면학회)
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Characteristics of the Adhesion Layer for the Flexible Organic Light Emitting Diodes

플렉시블 OLED 소자 제작을 위한 접합층 특성 연구

  • Cheol-Hee Moon (Department of Semiconductor Engineering, Hoseo University)
  • 문철희 (호서대학교 반도체공학과)
  • Received : 2023.07.07
  • Accepted : 2023.08.04
  • Published : 2023.09.30
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Abstract

To fabricate all-solution-processed flexible Organic Light-Emitting Diodes (OLEDs), we demonstrated a bonding technology using a polyethyleneimine (PEI) as an adhesion layer between the two substrates. As the adhesion layer requires not only a high adhesion strength, but also a high current density, we have tried to find out the optimum condition which meets the two requirements at the same time by changing experimental factors such as PEI concentration, thickness of the layer and by mixing some additives into the PEI. The adhesion strength and the electrical current density were investigated by tensile tests and electron only device (EOD) experiments, respectively. The results showed that at higher PEI concentration the adhesion strength showed higher value, but the electrical current through the PEI layer decreased rapidly due to the increased PEI layer thickness. We added Sorbitol and PolyEthyleneGlycohol (PEG) into the 0.1 wt% PEI solution to enhance the adhesion and electrical properties. With the addition of the 0.5 wt% PEG into the 0.1 wt% PEI solution, the device showed an electrical current density of 900 mA/cm2 and a good adhesion characteristic also. These data demonstrated the possibility of fabricating all-solution-processed OLEDs using two-substrate bonding technology with the PEI layer as an adhesion layer.

OLED 소자를 용액공정으로 제작함에 있어 음극 전극의 용액공정화가 기술적인 난제이므로 별도의 기판에 음극 전극을 형성하고 PEI 층을 접합층으로 사용하여 이를 다른 기판의 소자와 물리적, 전기적으로 연결하는 연구를 진행하였다. PEI 용액의 농도, PEI 층의 두께 및 첨가제 혼합 등을 변수로 하였으며 접착력 측정기와 EOD 소자 제작을 통하여 특성을 확인한 결과는 다음과 같다. PEI 용액의 농도가 높을수록 접착강도가 증가하였으나 막 두께의 증가로 전류 밀도가 감소하였다. 0.1 wt% PEI 용액에 첨가제로서 조비톨과 PEG를 혼합한 결과 PEG를 0.5 wt%의 농도로 혼합한 조건에서 900 mA/cm2 의 최대 전류 밀도를 얻었으며 양호한 접착 상태와 소자의 점등도 확인되었다.

Keywords

Acknowledgement

This research was supported by basic science Research Program through the National Research Foundation of Korea [NRF] funded by the Ministry of Education (grant number 2021R1F1A1056181) and by Korea Institute for Advancement of Technology (KIAT) grant funded by the Korea Government (MOTIE) (P0012453, The Competency Development Program for Industry Specialist).

References

  1. H. Zheng, Y. Zheng, N. Liu, N. Ai, Q. Wang, S. Wu, J. Zhou, D. Hu, S. Yu, S. Han, W. Xu, C. Luo, Y. Meng, Z. Jiang, Y. Chen, D. Li, F. Huang, J. Wang, J. Peng, and Y. Cao, Nat. Commun., 4, 1971 (2013)
  2. W. J. Zeng, H. B. Wu, C. Zhang, F. Huang, J. B. Peng, W. Yang, and Y. Cao, Adv. Mater., 19, 810 (2007).
  3. T. Cuk, S. M. Troian, C. M. Hong, and S. Wagner, Appl. Phys. Lett., 77, 2063 (2000).
  4. C. Zhong, C. Duan, F. Huang, H. Wu, and Y. Cao, Chem. Mater., 23, 326 (2011).
  5. W. Li, J. Li, and M. Wang, J. Chem.. 54, 867 (2014).
  6. M. Zhang and A. Colsmann, Nanoscale, 10, 1039 (2015).
  7. J. Ouyang and Y. Yang, Adv. Mater., 18, 2141 (2006).
  8. J. Liu, L. N. Lewis, T. J. Faircloth and A. R. Duggal, Appl. Phys. Lett., 88, 223509 (2006).
  9. C. H. Moon, Korean J. Met. Mater., 61, 175 (2023).
  10. S. Ghosh, S. Ganguly, S. Remanan and N. Ch Das, Compos. Sci. Technol., 181, 107682 (2019).
  11. S. Alvar, M. Blom, P.W.M. Blom & G. Wetzelaer, Nat. Commun., 11, 4023 (2020).
  12. S. R. Park, D. H. Shin, S. M. Park and M. C. Suh, RSC Adv., 7, 28520 (2017).
  13. Y. Zhao, R. Chen, Y. Gao, K. S. Leck, X. Yang, S. Liu, A. P. Abiyasa, Y. Divayana, E. Mutlugun, S. T. Tan, H. Sun, H. V. Demir and X. W. Sun, Org. Electron., 14, 3195 (2013).
  14. Y. H. Kim, T. H. Han, H. C. Cho, S. Y. Min, C. L. Lee and T. W. Lee, Adv. Funct. Mater., 24, 3808 (2014).
  15. H. S. Yoon and M. J. Kang, Korean patent 10-1688121 (2016).