Journal of the Semiconductor & Display Technology (반도체디스플레이기술학회지)

The Korean Society Of Semiconductor & Display Technology (한국반도체디스플레이기술학회)
권호 표지

Development of Micro-hemisphere Flexible PDMS Film for Enhancing Light Extraction in Organic Light-emitting Devices

유기발광소자의 광추출 향상을 위한 미세 반구형 유연 필름 연구

  • Baek, Dong-Hyun (Department of Display and Semiconductor Engineering, Sun Moon University) ;
  • Bae, Eun-Jeong (Department of Electrical Engineering, Korea University) ;
  • Maeng, Hyeongkyu (Department of Physics and Nano-Science, Sun Moon University) ;
  • Shin, Ji Soo (Department of Display and Semiconductor Engineering, Sun Moon University) ;
  • Park, Young Wook (Department of Display and Semiconductor Engineering, Sun Moon University)
  • 백동현 (선문대학교 디스플레이반도체공학과) ;
  • 배은정 (고려대학교 전기공학과) ;
  • 맹형규 (선문대학교 나노과학과) ;
  • 신지수 (선문대학교 디스플레이반도체공학과) ;
  • 박영욱 (선문대학교 디스플레이반도체공학과)
  • Received : 2022.08.09
  • Accepted : 2022.12.12
  • Published : 2022.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

We presented a micro hemi-sphere structure flexible film to improve the external quantum efficiency (EQE) in OLEDs. The micro hemi-sphere flexible film was fabricated with breath figure (BF) method and replica process. At 45 mg/mL of concentration, the size of the hemi-spheres was approximately 6.2 ㎛ were obtained which are the most circular shape. So, it was possible to yield the best performance with an improvement of 33 % in the EQE and the widest viewing angle ranging from 0° to 70°. As a result, the hemi-sphere film's size and distribution seem to play important roles in enhancing the EQE in OLEDs. Furthermore, the flexible hemi-sphere film based on polymeric materials could offer an effective, large-scale, mass-produced product and a simple process and approach to achieve high efficiency in flexible OLEDs.

Keywords

Acknowledgement

이 성과는 정부(과학기술정보통신부)의 재원으로 한국연구재단의 지원을 받아 수행된 연구임(No. 2020R1C1C1013567)과 2022년도 교육부의 재원으로 한국연구재단의 지원을 받아 수행된 지자체-대학 협력기반 지역혁신 사업의 결과입니다(2021RIS-004). 선문대학교 차세대반도체기술연구소의 분석지원에 감사드립니다.

References

  1. XU, R.-P., LI Y.-Q., et al. Recent advances in flexible organic light-emitting diodes. Journal of Materials Chemistry C 2016, 4, 9116-42. https://doi.org/10.1039/C6TC03230C
  2. LEO, K. Efficient and flexible solution. Nature Photonics 2011, 5, 716-8. https://doi.org/10.1038/nphoton.2011.288
  3. BURROWS, P., GU G., et al. Achieving full-color organic light-emitting devices for lightweight, flat-panel displays. IEEE Transactions on electron devices 1997, 44, 1188-203. https://doi.org/10.1109/16.605453
  4. BATHELT, R., BUCHHAUSER D., et al. Light extraction from OLEDs for lighting applications through light scattering. 2007, 8,293-9. https://doi.org/10.1016/j.orgel.2006.11.003
  5. ADACHI, C., BALDO M. A., et al. Nearly 100% internal phosphorescence efficiency in an organic light-emitting device. Journal of Applied Physics 2001, 90, 5048-51. https://doi.org/10.1063/1.1409582
  6. CHUTINAN, A., ISHIHARA K., et al. Theoretical analysis on light-extraction efficiency of organic light-emitting diodes using FDTD and mode-expansion methods. Organic electronics 2005, 6, 3-9. https://doi.org/10.1016/j.orgel.2004.12.001
  7. SCHOLZ, S., KONDAKOV D., et al. Degradation mechanisms and reactions in organic light-emitting devices. Chemical reviews 2015, 115, 8449-503. https://doi.org/10.1021/cr400704v
  8. MoLLER, S., FORREST S. Improved light out-coupling in organic light emitting diodes employing ordered microlens arrays. Journal of Applied Physics 2002, 91, 3324-7. https://doi.org/10.1063/1.1435422
  9. GALEOTTI, F., MRoZ W., et al. Microlens arrays for light extraction enhancement in organic light-emitting diodes: a facile approach. Organic Electronics 2013, 14, 212-8. https://doi.org/10.1016/j.orgel.2012.10.034
  10. BOCKSROCKER, T., HOFFMANN J., et al. Micro-spherically textured organic light emitting diodes: a simple way towards highly increased light extraction. Organic Electronics 2013, 14, 396-401. https://doi.org/10.1016/j.orgel.2012.10.036
  11. KIM, H. S., MOON S. I., et al. Novel fabrication method of microlens arrays with High OLED out-coupling efficiency. Optics Laser Technology 2016, 77, 104-10. https://doi.org/10.1016/j.optlastec.2015.09.006
  12. CHARI, K., LANDER C. W., et al. Anamorphic microlens arrays based on breath-figure template with adaptive surface reconstruction. Applied Physics Letters 2008, 92, 111916. https://doi.org/10.1063/1.2901027
  13. LI, L., ZHONG Y., et al. Breath figure lithography: A facile and versatile method for micropatterning. Journal of colloid interface science 2010, 342, 192-7. https://doi.org/10.1016/j.jcis.2009.10.005
  14. WU, C. Y., CHIANG T. H., et al. Fabrication of microlens array diffuser films with controllable haze distribution by combination of breath figures and replica molding methods. Optics express 2008, 16, 19978-86. https://doi.org/10.1364/OE.16.019978
  15. CHENG, C. X., TIAN Y., et al. Porous polymer films and honeycomb structures based on amphiphilic dendronized block copolymers. Langmuir 2005, 21, 6576-81. https://doi.org/10.1021/la050187d
  16. WANG, C., MAO Y., et al. Fabrication of highly ordered microporous thin films by PS-b-PAA self-assembly and investigation of their tunable surface properties. Journal of Materials Chemistry 2008, 18, 683-90. https://doi.org/10.1039/b715520d
  17. CONNAL, L. A., VESTBERG R., et al. Dramatic morphology control in the fabrication of porous polymer films. Advanced Functional Materials 2008, 18, 3706-14. https://doi.org/10.1002/adfm.200800568