2D flexibele organic led lighting made by the mile on a roll
“An Organic Light Emitting Diode, or OLED, is in essence a sheet of organic material that lights up when you drive an electric current through it. It’s not a point source of light and the sheet has no pixels; it is a continuous two-dimensional light source,” explains Date Moet of TMC.
The project he is working on is called Flex-o-Fab and it is a EU-funded collaboration between twelve companies and institutes from across Europe – all with strong backgrounds in organic electronics. Date Moet has been with TMC for almost five years now and has been project manager for Flex-o-Fab for over a year. “OLEDs are built up of multiple, very thin layers. The goal is to produce the OLEDs using a roll-to-roll (R2R) process, ‘printing’ the layers like we print newspapers. Normally the OLEDs are made by the sheet, on glass, in a sheet-to-sheet process. The glass is necessary because the organic material is very sensitive and needs to be protected from air and water, or it will degrade rapidly. The goal of this project is to make the first part of the production process roll-to-roll and after that finish the OLEDs in sheets. We’ve recently had a breakthrough which is a big step towards making this possible. We were able to create a high-performance flexible barrier foil that does the exact same thing as the glass, keep the moisture out, but is very thin and flexible. We were able to produce 2.5 kilometres of the barrier foil and ‘print’ it on a flexible PET foil in a roll-to-roll process.”
Flexible OLEDs made in a roll-to-roll process will create many interesting possibilities. Date explains: “By making the OLEDs flexible and the production roll-to-roll, we can produce them much more cheaply and thus make them more available for commercial use. The flexibility in itself also creates a lot of new applications. Think about the possibilities in textiles, architecture or in the design of lighting in our houses. With thin flexible OLEDs practically everything can become a light source. And maybe even more interesting is that the production process of the barrier foil can also be used for other technologies such as mobile displays or solar cells.”
With the barrier foil, the first big step has been taken towards making the production of OLEDs roll-to-roll, but there is still much work to be done. “Flex-o-Fab is a three-year project that will run until September 2015. In the coming months, we want to demonstrate this technology’s feasibility in a pilot series demonstration. Within three years after this project our aim is for the technology to be mature enough to produce flexible OLEDs in a real production environment. The next step would be to make the first electrode layer – the anode –in a roll-to-roll process. In the longer term, all the other layers, until finally the whole OLED is produced like printing a newspaper.”