Surface properties of the ITO electrode and the bank resist structure are critical to both the electrical and optical performance of PLED displays. To assure the best pixel formation and maximum luminosity, the ink jet printing of PLED materials requires a very specific surface preparation. This surface engineering is performed using PVA TePla’s unique planar microwave plasma technology, producing precisely the desired surface energy on the bank structure and the ITO-surface. The TePla process allows to selectively generate hydrophilic and hydrophobic surface conditions for controlled pixel filling and ink flow. Additionally, increasing the ITO work-function prior to LEP deposition greatly improves the efficiency of charge transport into the organic layers.