Highly conductive PEDOT:PSS and graphene oxide hybrid film from a dipping treatment with hydroiodic acid for organic light emitting diodes

Using a simple and low temperature dipping treatment in hydriodic acid (HI) solution, we have fabricated a highly conductive and transparent poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) and graphene oxide (GO) hybrid film. The HI treated PEDOT: PSS with 0.01 wt% GO hybrid film can obtain a highest conductivity of about 1290 S cm(-1). The enhancement in the conductivity is mainly caused by the removal of the PSS chains of PEDOT: PSS and functional groups on the GO sheets from the hybrid film surface after the film undergoes dipping treatment in HI solution. The remaining PEDOT domains together with the reduced GO sheets can provide more conductive pathways for carriers and improve the conductivity of the film. After mixing with the reduced GO sheets, the air stability of the PEDOT: PSS hybrid film is also dramatically improved. Using the HI-treated PEDOT: PSS: GO hybrid film as an anode, we have successively fabricated organic light emitting diodes, which show higher current density and luminance values compared to those with indium tin oxide as an anode.