期刊
ORGANIC ELECTRONICS
卷 89, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.orgel.2020.106057
关键词
OLEDs; Light extraction; Transparent electrodes; External quantum efficiency
资金
- Ministry of Science and Technology of Taiwan [MOST 107-2221-E-002-160-MY3, 108-2221-E-002-148-MY3]
- Ministry of Education (MOE)
- Ministry of Science and Technology (MOST) of Taiwan
This study investigates the influence of bottom transparent electrode thickness on emission properties of OLEDs through simulation and experiments. By using a very thin ITO electrode and horizontal dipole emitters, the overall coupling efficiencies and external quantum efficiency of OLED emission into substrates can be greatly enhanced. The potential of using thin transparent electrodes for highly efficient OLEDs is clearly revealed.
High-index transparent electrodes have been one major origin of light trapping and lower light extraction in organic light emitting diodes (OLEDs). In this work, influences of the bottom transparent electrode thickness on emission properties of OLEDs are systematically studied by both simulation and experiments. Simulation shows that with substantially decreasing the thickness of the high-index indium tin oxide (ITO) electrode, waveguided modes, that otherwise would be significantly induced in regular/thicker ITO devices, can be effectively eliminated. Consequently, the overall coupling efficiencies of OLED emission into substrates can be much enhanced. Through further effective light extraction from the substrate, green phosphorescent OLEDs with a high external quantum efficiency (EQE) of up to approximate to 57.5% were experimentally demonstrated by adopting the very thin (20 nm) ITO electrode and preferentially horizontal dipole emitters (with a horizontal dipole ratio of 76%). The simulation further predicts that very high optical coupling efficiencies into substrates and EQEs approaching 80% are possible with further adopting purely horizontal dipole emitters and/or low-index electron transport layer (ETL) to suppress surface plasmon modes. Overall, this study clearly reveals the potential of using thin transparent electrodes for highly efficient OLEDs.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据