Multifunctional oxides for integrated manufacturing of efficient graphene electrodes for organic electronics

Using multi-functional oxide films, we report on the development of an integration strategy for scalable manufacturing of graphene-based transparent conducting electrodes (TCEs) for organic electronics. A number of fundamental and process challenges exists for efficient graphene-based TCEs, in particular, environmentally and thermally stable doping, interfacial band engineering for efficient charge injection/extraction, effective wetting, and process compatibility including masking and patterning. Here, we show that all of these challenges can be effectively addressed at once by coating graphene with a thin (>10 nm) metal oxide (MoO3 or WO3) layer. We demonstrate graphene electrode patterning without the need for conventional lithography and thereby achieve organic light emitting diodes with efficiencies exceeding those of standard indium tin oxide reference devices.Funding from EU FP7 programme Grafol (Grant No. 285275) and EPSRC (Grant No. EP/K016636/1, GRAPHTED) was acknowledged. P.R.K. acknowledges the Lindemann Trust Fellowship.This is the author accepted manuscript. The final version is available from AIP via http://dx.doi.org/10.1063/1.490829