Negative mold transfer patterned conductive polymer electrode for flexible organic light-emitting diodes

We demonstrate flexible organic light-emitting diodes (FOLEDs) that use flexible conductive polymer electrodes patterned by negative mold transfer printing (nMTP). Because pristine poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is unsuitable for nMTP owing to problems with wettability, additives are used to improve the surface wetting properties of the polymer on the mold to successfully employ nMTP. Moreover, the additives improve the conductivity of the polymer electrode. FOLEDs fabricated with the modified PEDOT:PSS using nMTP exhibit electrical properties comparable to those of a device having an indium tin oxide (ITO) anode. These results show that the highly conductive PEDOT:PSS patterned by nMTP can be used as transparent high-resolution electrodes in low-cost ITO-free FOLEDs.