UV-induced modulation of the conductivity of polyaniline: towards a photo-patternable charge injection layer for structured organic light emitting diodes

Abstract

In macromolecular electronics the organic material should offer—besides the desired electronic properties—the possibility of lateral patterning. Here, we report on a novel polyaniline derivative bearing photosensitive N-formamide groups. UV illumination of this polymeric material leads to a decarbonylation reaction resulting in polyaniline which can be subsequently protonated to yield the conductive emeraldine salt. Due to the fact that the conductivity depends on the conversion of the photoreaction, a selective adjustment of the conductivity by means of UV light is feasible. These photo-induced conductivity changes were corroborated in thin films by conductive AFM measurements. Further, we demonstrate the versatility of this polymer with respect to a patterned modification of the conductivity as well as its application as a photo-patternable charge injection layer for structured OLEDs. This makes the new polymer an interesting candidate for electrodes and interconnects in various organic electronic devices.