Flame synthesis of graphene films in open environments

Few-layer graphene is grown on copper and nickel substrates at high rates using a novel flame synthesis method in open-atmosphere environments. Transmittance and resistance properties of the transferred films are similar to those grown by other methods, but the concentration of oxygen, as assessed by X-ray photoelectron spectroscopy, is actually less than that for graphene grown by chemical vapor deposition under near vacuum conditions. The method involves utilizing a multi-element inverse-diffusion-flame burner, where post-flame species and temperatures are radially-uniform upon deposition at a substrate. Advantages of the specific flame synthesis method are scalability for large-area surface coverage, increased growth rates, high purity and yield, continuous processing, and reduced costs due to efficient use of fuel as both heat source and reagent. Additionally, by adjusting local growth conditions, other carbon nanostructures (i.e. nanotubes) are readily synthesized.