Improvement of light extraction efficiency and reduction of driving voltage in organic light emitting diodes using a plasmonic crystal
- Advanced Device Laboratory, RIKEN, Hirosawa, Wako, Saitama 351-0198 (Japan)
- Advanced Technology Laboratory, Oji Holding Corporation, Shinonome, Koto-ku, Tokyo 135-8558 (Japan)
Two-dimensional periodic corrugation was introduced into the surface of metallic cathodes of organic light-emitting diodes (OLEDs) to extract surface plasmon energy, which is trapped in that surface, as free-space photons. The dependence of the improvement factor of the emission efficiency on the modulation depth of the corrugation was systematically investigated. The corrugation was fabricated by using a colloidal lithography technique, which can be easily applied to a wide area. The obtained maximum improvement factor in current efficiency was 1.67 for an OLED with a 40 nm modulation depth, whereas the improvement in power efficiency was 2.35 for an OLED with a 60 nm modulation depth. We attributed the former improvement factor purely to optical effects and the latter to both optical and electrical effects, namely, a reduction of the electrical resistance of the organic layers due to the introduced corrugation.
- OSTI ID:
- 22283094
- Journal Information:
- Applied Physics Letters, Vol. 104, Issue 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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