Graphene Nano-patches on a Carbon Nanotube Network for Highly Transparent/Conductive Thin Film Applications

Freestanding carbon-based composite thin films, consisting of a carbon nanotube network patched with graphene sheets, were assembled by a solid-phase layer-stacking approach with ethanol wetting. The composite films are highly flexible, transparent, and conductive, showing a sheet resistance of 735 Omega/sq at 90% transmittance (at 550 nm). Under AM 1.5 illumination, heterojunction solar cells made from the composite films and n-type silicon show a power conversion efficiency of up to 5.2%.