CVD graphene recrystallization as a new route to tune graphene structure and properties

We report here on a new way to tailor the structure of large-scale graphene during its growth. Monolayer graphene formed on Pt substrate using a modified hot-filament-assisted chemical vapor deposition setup, which does not require any control of crystal nucleation and orientation. The underlying growth mechanism includes a stage of structural evolution from nanocrystalline to microcrystalline graphene film. An enhanced recrystallization process in the graphene film is assessed by means of Raman spectroscopy and atomic resolution transmission electron microscopy. Moreover we demonstrate that the rotational angle between neighboring graphene grains can be tuned to 30° or to small misalignment about 1-2° only. This process opens a new route to control the electrical properties of large-scale uniform graphene film.