Korean Journal of Optics and Photonics (한국광학회지)

Optical Society of Korea (한국광학회)
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Simulation of the Combined Effects of Dipole Emitter Orientation, Mie Scatterers, and Pillow Lenses on the Outcoupling Efficiency of an OLED

쌍극자 광원의 진동방향, Mie 산란자, 그리고 Pillow 렌즈가 OLED의 광추출효율에 미치는 영향에 대한 시뮬레이션 연구

  • 이주섭 (한림대학교 전자물리학과) ;
  • 이종완 (한림대학교 전자물리학과) ;
  • 박재훈 (한림대학교 전자공학과) ;
  • 고재현 (한림대학교 전자물리학과)
  • Received : 2014.06.19
  • Accepted : 2014.07.17
  • Published : 2014.08.25
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Abstract

The net effect of the emitter orientation, Mie scatters, and pillow lenses on the outcoupling efficiency (OCE) of a bottom-emitting OLED having an internal photonic crystal layer was investigated by a combined optical simulation based on the finite-difference time-domain method (FDTD) and the ray-tracing technique. The simulation showed that when the emitter orientation was horizontal with respect to the OLED surface, the OCE could be increased by 54% when a photonic crystal layer was employed, while it could be improved by 86% under optimized conditions of Mie scatters and pillow lenses applied to the glass substrate. The peculiar intensity distribution of the OLED, caused by the periodic lattice structure of the photonic crystal layer, could be ameliorated by inserting Mie scatters into the glass substrate. This study suggests that conventional outcoupling structures combined with control of the emitter orientation could improve the OCE substantially.

본 연구에서는 FDTD와 광선추적기법을 결합한 시뮬레이션을 활용해 광원으로 설정된 쌍극자의 진동 방향, 유리기판에 적용된 Mie 산란입자와 Pillow 렌즈가 광결정 구조가 포함된 OLED의 광추출효율에 미치는 영향을 조사하였다. 쌍극자 광원의 진동방향이 OLED 표면에 대해 수평인 경우, 광결정구조만 적용된 OLED의 효율이 54%인데 반해 최적화된 조건의 Mie 산란입자, Pillow 렌즈가 적용된 OLED는 약 86%의 광추출효율을 나타냈다. 아울러 광결정 구조로 인해 특정 각도로 광도가 증가하는 문제점이 Mie 산란입자의 산란효과로 인해 완화될 수 있음을 알았다. 본 연구는 광추출효율을 향상시키는 다양한 광학구조를 적용함과 더불어 발광체 유기분자의 배향을 조절함으로써 OLED의 효율을 큰 폭으로 향상시킬 수 있음을 보여준다.

Keywords

References

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