R2Flex - Incandescent lamp: the way of the dodo

Area of relevance: 
1 January 2007 - 31 May 2012
Institute of Applied Photophysics, TU Dresden, Germany
Funded by: 
German Federal Ministry of Education and Research (BMBF), Germany


Organic Light Emitting Diodes (OLEDs) are a promising candidate for the replacement of the inefficient incandescent lamp. Compared to other lighting technologies, OLEDs can combine a very high power efficiency, a good color quality with new luminaire designs such as OLEDs on large area, flexible foils. For the commercial success of the OLED technology, a reduction of the production costs is essential. In the scope of this project a technology for the roll-to-roll fabrication of highly efficient OLEDs on flexible metal foils is developed, which will meet this target. However, the deposition of OLEDs onto rough and opaque substrates such as metal foils bears scientific challenges: The OLEDs have to emit light through a thin, metallic top electrode, and due to the roughness of the low-cost substrates, the OLEDs are prone to shortcuts. This can be solved by the use of the pin OLED technology employing thick doped layers and a thorough optical optimization of the OLED micro-cavity. Besides the scientific challenges, the research is focused on the roll-to-roll processing technology of OLEDs on metal foils. Novel evaporation sources are introduced that can reach high deposition rates and a thin film encapsulation technology is optimized that protects the OLEDs from the normal atmosphere and leads to long-living OLEDs. Combining technological expertise with scientific research will lead to further improvements in performance of OLEDs produced on a Roll-to-Roll coater.