Abstract
Out-coupling enhanced organic light-emitting diodes (OLEDs) with micro-lens arrays and a nano-scale periodic light-extraction structure - a photonic crystal (PC) - utilizing laser interference lithography (LIL) are demonstrated. Generally, PC-based OLEDs suffer from a distorted and shifted spectrum, despite a highly improved intensity. However, in this study, we demonstrate PC-based OLEDs with a distortion-free spectrum and a highly improved out-coupling performance. It was found that spectrum distortion decreased with the pitch size of the PC. The PC-based OLED with a 250 nm pitch size showed a dramatically reduced spectral shift: International Commission on Illumination 1931 color coordinate of (Δ0.00, Δ0.00) and Δpeak wavelength of 0 nm as compared with the reference. Simultaneously, the external quantum efficiency and the power efficiency were enhanced by up to 178% and 264%, respectively, as compared with the reference. Moreover, through the LIL, simple and maskless processes were achieved for a light-extraction structure over a large area.
Original language | English |
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Pages (from-to) | 111-117 |
Number of pages | 7 |
Journal | Organic Electronics |
Volume | 15 |
Issue number | 1 |
DOIs | |
Publication status | Published - 2014 |
Keywords
- Laser interference lithography (LIL)
- Micro-lens arrays
- Nano-scale periodic pattern
- Organic light-emitting diodes (OLEDs)
- Out-coupling
- Photonic crystal
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- Chemistry(all)
- Condensed Matter Physics
- Materials Chemistry
- Electrical and Electronic Engineering