Flexible OLED from the Roll

The joint OLED project R2Flex has been successfully finished. As a result, Fraunhofer COMEDD and Tridonic Dresden (formerly LEDON OLED Lighting) present a demonstrator of a desk luminaire with flexible OLED. The joint project R2Flex dealt with the production of highly efficient organic devices on flexible substrates, manufactured in a roll-to-roll process technology. R2Flex was funded by the Federal Ministry for Education and Research (BMBF) with a total sum of about €11 million over a period of 2.5 years.

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.

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.

Next to the manufacturing of OLED on flexible substrates, aspects of their integration for possible products have also been investigated by Tridonic Dresden GmbH & Co. KG. 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.

As a result of the joint project R2Flex, a demonstrator in form of a gracile desk luminaire could be manufactured. 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 and Tridonic Dresden GmbH & Co. KG, 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).