Gravure printed PEDOT: PSS as anode for flexible ITO-free organic light emitting diodes

Roll-to-roll gravure printing is considered as potential leading manufacturing technology for flexible, low cost and large area optoelectronics. However, solution processed multilayer organic electronics are still challenging to be produced, especially in the case of electrodes. In this work, the gravure printing technique was successfully employed to realize the highly conductive poly(3,4ethylenedioxythiophene): poly(styrene sulfonate) (PEDOT: PSS) polymeric anode and tested for the first time in flexible ITO-free (Indium Thin Oxide) organic light emitting diodes (OLEDs). The device performances were found to be similar to those of a reference device containing a spin-coated polymeric anode. A gravure printed dimethyl sulfoxide (DMSO) post-treatment was successfully tried to improve the printed anode characteristics. The obtained results show the way for future development for processing flexible ITO-free devices using the most attractive printing technology for roll-to-roll large area manufacturing.