Graphene-based nanolaminates as ultra-high permeation barriers

Permeation barrier films are critical to a wide range of applications. In particular, for organic electronics and photovoltaics not only ultra-low permeation values are required but also optical transparency. A laminate structure thereby allows synergistic effects between different materials. Here, we report on a combination of chemical vapor deposition (CVD) and atomic layer deposition (ALD) to create in scalable fashion few-layer graphene/aluminium oxide-based nanolaminates. The resulting ~10 nm contiguous, flexible graphene-based films are >90% optically transparent and show water vapor transmission rates below 7 × 10¯³g/m²/day measured over areas of 5 × 5 cm². We deploy these films to provide effective encapsulation for organic light-emitting diodes (OLEDs) with measured half-life times of 880 h in ambient.We acknowledge funding via EPSRC-Innovate UK Grant (EP/M507751/1). B.C.B acknowledges funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreements 656214- 2DInterFOX. J.C.M. acknowledges support from the Austrian Science Fund (FWF, P25721-N20)