Journal of IKEEE (전기전자학회논문지)

Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
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Roll-to-roll microcontact-printed microlens array for light extraction film of organic light-emitting diodes

유기발광다이오드의 외부 광추출층을 위한 롤투롤 마이크로컨택 방식으로 인쇄된 마이크로렌즈 어레이

  • Hwa, Subin (Dept. of Creative Convergence Engineering, Hanbat National University) ;
  • Sung, Baeksang (Dept. of Creative Convergence Engineering, Hanbat National University) ;
  • Lee, Jae-Hyun (Dept. of Creative Convergence Engineering, Hanbat National University) ;
  • Lee, Jonghee (Dept. of Creative Convergence Engineering, Hanbat National University) ;
  • Kim, Min-Hoi (Dept. of Creative Convergence Engineering, Hanbat National University)
  • Received : 2022.05.12
  • Accepted : 2022.06.07
  • Published : 2022.06.30
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Abstract

We demonstrated roll-to-roll microcontact printed (mCP) microlens array (MLA) to enhance the light extraction of organic light emitting diodes (OLEDs). The commercially provided microlens array is used as a template for polydimethylsiloxane (PDMS) roll stamp. The fluorinated film is formed on the PDMS roll stamp from fluorinated ink with low boiling point and printed onto the bottom side of the organic light emitting diode without high pressure and high thermal treatment. With optimized concentration of ink, the pattern which is almost identical to that of the template MLA was successfully printed. Due to the structure and low optical absorbance of microcontact printed MLA, the external quantum efficiency of OLED was improved by about 18%.

본 연구에서는 유기 발광 다이오드(OLED)의 광추출 향상을 위한 롤투롤 마이크로컨택(mCP)방식으로 인쇄된 마이크로렌즈 어레이(MLA)를 제시하였다. 상업적으로 사용되는 마이크로렌즈 어레이를 템플레이트로 사용하여서 polydimethylpolysiloxane(PDMS)를 롤스탬프로 제작하였다. 낮은 끓는 점을 가지는 불소화 잉크로부터 PDMS 롤스탬프에 고분자 박막을 형성하고 이를 OLED의 하부면에 고압·고온 처리 없이 인쇄하였다. 최적화된 농도를 찾아서 템플레이트로 사용된 MLA와 거의 동일한 모양의 패턴을 성공적으로 인쇄하였다. 마이크로컨택 방식으로 인쇄된 MLA의 구조와 소재의 낮은 흡수도로 인해서 OLED의 외부양자효율이 18% 향상되었다.

Keywords

Acknowledgement

This paper was supported by the Basic Science Research program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2018R1A6A1A03026005) and by Korea Institute for Advancement of Technology (KIAT) grant funded by the Korea Government (MOTIE) (P0012744, HRD program for industrial innovation).

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