The joint OLED project R2
The overall aim of the joint project R2Flex included the development of essential components for highly efficient OLED technology. The OLED should be processed in a roll-to-roll process technology on cost-effective substrates, especially on metal foil. This technological approach should help to solve a main problem of the production of OLED: to be able to offer and use OLED for lighting and signage applications, low costs are essential. This key fact could not be achieved by the conventional technology approaches because of the high costs of the coating technologies and materials.
OLED roll-to-roll technology for flexible substrates
Fraunhofer COMEDD has improved its roll-to-roll research line, which consists of a vacuum system for the evaporation of organic materials. Furthermore, it includes a coating and lamination system, which can be used under nitrogen atmosphere, and an optical inspection system for defect control and processes monitoring on flexible foils. Within the R2Flex project the OLED technology of established processes could successfully be transferred from rigid substrates to roll-to-roll processes. Especially, the processes for patterning of substrates and encapsulation of the foils were developed. However, one of the most important key challenges of the investigations was the deposition technology of complex OLED structures. To achieve e.g. white OLED, many different layers with a layer thickness in the range of several nanometers have to be deposited precisely on top of each other. Performing this process within a roll-to-roll line was a complex task. Nevertheless, a white OLED could be demonstrated successfully on metal foil.
OLED product integration
Next to the manufacturing of OLED on flexible substrates also aspects of their integration for possible products have been investigated by Tridonic Dresden GmbH & Co. KG. Therefore, Tridonic Dresden evaluated technologies for the secure and cost-efficient electrical contacting of flexible OLED on metal substrates and their integration in luminaires. Resulting from this the problem of contacting through the barrier film could be solved together with Fraunhofer COMEDD. Such a solution has been integrated successfully into the roll-to-roll research line of Fraunhofer COMEDD.
Project results combined in a desk luminaire
As a result of the joint project R2Flex a demonstrator in form of a gracile desk luminaire could be manufactured. Therefore, two flexible OLED on metal substrate have been used, which were produced at Fraunhofer COMEDD. The modules were serially connected via flexible contacting. The luminaire combines both straight and curved shapes. The curved shape of the head section of the luminaire impressively presents the flexibility of the OLED. The reduced and open design highlights the flexible OLED in an attractive and esthetic way.
Besides Fraunhofer COMEDD (Förderkennzeichen: 13N11058) and Tridonic Dresden GmbH & Co. KG (formerly LEDON OLED Lighting GmbH & Co. KG) (Förderkennzeichen: 13N11061) the TU Dresden with the Institute for Applied Photophysics (IAPP, leader of the consortium), the Fraunhofer Institute for Electron Beam and Plasma Technology (FEP), Novaled AG, Heliatek GmbH, VON ARDENNE Anlagentechnik GmbH, Creaphys GmbH, 3D-Micromac AG, LayTec GmbH and ALANOD Aluminium-Veredelung GmbH & Co. KG were partners within the project funded by the Federal Ministry for Education and Science (BMBF).
An organic light-emitting diode (OLED) consists of a thin organic system of layers (about 200 to 400 nanometers), which lies between two electrodes (anode and cathode). In total this area light source, which is evaporated in vacuum on flexible foil or metal substrates, is thinner than two millimeters. By applying electrical current light is been generated within the system of layers and emits through one of the electrodes. In contrast to conventional light sources OLED light modules spread an area light with a high color quality, which is very pleasant for the human eye. Another advantage: the area light of OLED does not blind. Thus OLED do not need any reflectors to minimize the dazzle effect. In general OLED belong to some of the most efficient light sources.
About Tridonic Dresden
Since July 2013 Tridonic Dresden GmbH & Co. KG is a 100% subsidiary of the Zumtobel Group. Originally Tridonic Dresden was founded as a joint-venture company under the leading of LEDON OLED Lighting GmbH & Co. KG by the Zumtobel Group together with the Fraunhofer Gesellschaft and some employees of the Fraunhofer Institute for Photonic Microsystems (IPMS) in autumn 2009. The head office is in Dresden - one of the most important centers for OLED technology in Europe.
Main aim of Tridonic Dresden is the further processing and finishing of OLED lighting elements to applicable OLED modules. Some of our core competencies are the electrical integration and electronically control and driving of OLED light modules as well as the improvement of the quality of light.
Source and top image: Fraunhofer COMEDD
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