Enhanced light extraction in ITO-free OLEDs using double-sided printed electrodes.

We show how nanoimprint lithographic techniques are particularly suited for the realization of OLED device structures. We tested them to realize nanopatterned metallic electrodes containing photonic crystals to couple the light out and plasmonic crystals showing extraordinary transmission. At similar current densities, a two-fold electroluminescence is achieved with devices having double-sided structured metallic electrodes as compared to a control OLED with an ITO anode. The use of combined nanoimprint lithography processes has the potential to expand the performance range of various organic optoelectronic devices.