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NTIS 바로가기한국광학회지 = Korean journal of optics and photonics, v.26 no.3, 2015년, pp.139 - 146
이성준 (한림대학교 전자물리학과) , 고재현 (한림대학교 전자물리학과)
The effects of a dielectric multilayer mirror on the efficiency of organic light-emitting diodes (OLEDs) were investigated by using optical simulation. Adoption of a dielectric mirror consisting of alternating SiN and
핵심어 | 질문 | 논문에서 추출한 답변 |
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유기발광다이오드란? | 유기발광다이오드(Organic Light Emitting Diode, OLED)는 두 전극 사이에 위치한 유기발광물질에 의한 발광 현상을 이용하는 소자로써, 최근 고해상도 디스플레이 이 외에 일반 조명으로 적용 분야가 확장되고 있다. 최근 시장이 확대되고 있는 고해상도 OLED TV의 성장세는 이제 OLED 기술이 대형 디스플레이 시장으로 잠입해 들어가고 있음을 보여주는 것이다. | |
OCE를 향상시키기 위한 다양한 광학 구조에는 어떤 것들이 있는가? | 순수하게 기하광학적 고려만을 하게 되면 발생한 빛의 20% 미만이 에어 모드로 빠져나가는 것으로 계산된다 [3]. 그 동안 많은 연구자들에 의해 OCE를 향상시키기 위한 다양한 광학 구조가 제안되어 왔는데, 마이크로렌즈 혹은 확산층을 활용해 기판모드를 추출하는 방법[5-12], 도파관 모드로 갇히는 빛을 빼내기 위해 OLED의 내부 구조를 다양하게 변형시키는 접근 방법[13-20], 플라스몬 손실을 줄이거나[21] 다양한 접근법들을 동시에 적용하는 하이브리드 방법[22, 23], 발광층 내 발광자의 방향을 조절하는 방법[24-31] 등이 시도되어 왔다. | |
OLED가 가지는 미소공진(microcavity) 구조의 원리는? | 또 하나의 접근 방법은 OLED가 가지는 미소공진(microcavity) 구조를 이용하는 것이다 [32-51]. 배면발광형 OLED는 기본적으로 음극인 금속과 양극인 투명전극 사이에 약한 미소공진 구조가 형성되는데, 이 때 금속이나 유전체 다층박막 등으로 공진구조를 강화시키면 OLED 발광색의 순도가 강화되어 색재현성이 증가하거나 발광효율의 상승을 기대할 수 있다. 양극 쪽의 거울로는 얇은 금속 거울 외에 서로 다른 굴절률을 가진 물질을 교대로 형성한 다층 박막형 유전체 거울[35-37, 39-41]이나 유전체-거울-유전체 구조[51]가 적용되기도 하였다. |
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