Flexible OLED Lamp Developed Using Transparent Resin Electrodes
AGFA-Gevaert NV and IMEC of Belgium, and Holst Centre, Philips Research and TNO of the Netherlands announced that they have prototyped a 12 x 12cm flexible OLED lighting panel by using highly-conductive transparent resin electrodes in place of ITO (indium tin oxide).
So far, it has been difficult to secure enough electrical conductivity of ITO in a low-temperature process. The new transparent resin has a high conductivity and is suited for coating method. Therefore, it is relatively easy to use the resin in a printing process. For the development, the companies received support from "Fast2Light," the European Union's project aimed at manufacturing flexible OLED lamps by a printing process.
The transparent resin, which is called "Orgacon," was developed by AGFA as a static protection material for photographic films. It is based on PEDOT/PSS, a conductive resin used for OLED devices. Sanyo Electric Co Ltd and the Tokyo Institute of Technology, too, are developing a similar material (See related article).
OLED lighting panels are normally manufactured by stacking ITO and PEDOT/PSS thin films for transparent electrodes. This time, the companies used the Orgacon instead of ITO and improved the electrical conductivity of the transparent electrodes by about six times, according to AGFA. But they did not reveal the details such as a specific value of the conductivity.
The prototyped OLED lighting panel was made by using more printing processes than before. For example, its wiring pattern on the transparent electrodes was printed by inkjet technology. Also, the panel can be bent by the hand because it uses metal foil as a substrate. Its luminance and emission lifetime have not been disclosed yet.