Inkjet printing as a roll-to-roll compatible technology for the production of large area electronic devices on a pre-industrial scale

Inkjet printing is a promising approach towards the solution processing of electronic devices on an industrial scale. Of particular interest is the production of high-end applications such as large area OLEDs on flexible substrates. Roll-to-roll (R2R) processing technologies involving inkjet printing have especially high potential, since they allow a continuous production of large volumes with high throughput. Here we report on our research activities to scale up printed OLED production on foils to an industrial scale. When building up the device, necessarily deposition will have to be done on very different types of surfaces, some of which are highly prone to damage upon mechanical load. Inkjet printing as a non-impact technology is therefore expected to have decisive advantages compared to e. g. screen printing. We have evaluated both methods for silver shunt line deposition on a barrier layer which protects the OLED against humidity. Screen printing on the barrier layer resulted in a significantly higher number of defects than did inkjet printing. For post-deposition treatment we have used photonic flash sintering as a highly efficient and R2R compatible method. We were thus able to demonstrate that a core step of OLED production can be carried out by R2R processing. Finally, our efforts resulted in the production of fully functional large area OLED devices, with inkjet printed silver shunt lines. Our future plans include moving towards fully integrated R2R production of OLEDs to demonstrate this concept's feasibility for industrial scale manufacturing. cop. 2014 Society for Imaging Science and Technology