상세정보
학술지
Overcoming the Efficiency Limit of Organic Light-emitting Diodes using Ultra-thin and Transparent Graphene Electrodes
- 발행일
- 201801
- 출처
- Optics Express, v.26 no.2, pp.617-626
- ISSN
- 1094-4087
- 출판사
- Optical Society of America(OSA)
- 협약과제
- 17PB3300, 그래핀 소재의 OLED 투명전극과 박막봉지 적용을 위한 2세대 이상 기판 기반의 플렉서블 OLED 소자/패널 기초 및 응용 기술 개발, 이정익
- 초록
- We propose an effective way to enhance the out-coupling efficiencies of organic light-emitting diodes (OLEDs) using graphene as a transparent electrode. In this study, we investigated the detrimental adsorption and internal optics occurring in OLEDs with graphene anodes. The optical out-coupling efficiencies of previous OLEDs with transparent graphene electrodes barely exceeded those of OLEDs with conventional transparent electrodes because of the weak microcavity effect. To overcome this issue, we introduced an internal random scattering layer for light extraction and reduced the optical absorption of the graphene by reducing the number of layers in the multilayered graphene film. The efficiencies of the graphene-OLEDs increased significantly with decreasing the number of graphene layers, strongly indicating absorption reduction. The maximum light extraction efficiency was obtained by using a single-layer graphene electrode together with a scattering layer. As a result, a widened angular luminance distribution with a remarkable external quantum efficiency and a luminous efficacy enhancement of 52.8% and 48.5%, respectively, was achieved. Our approach provides a demonstration of graphene-OLED having a performance comparable to that of conventional OLEDs.
- KSP 제안 키워드
- External Quantum Efficiency, Number of graphene layers, Number of layers, Organic light-emitting diodes(OLEDS), Scattering layer, Ultra-thin, efficacy enhancement, efficiency limit, graphene anode, graphene electrode, graphene films