Large-area layer-by-layer controlled and fully bernal stacked synthesis of graphene

As semi-metallic monolayer graphene is limited in broadening the applications, synthesis of multi-layer graphene has recently attracted intense interests to enable functional optoelectronic devices. However, controlling the growth of multiple graphene layers is still quite challenging since the process critically depends on self-limited growth and interaction between graphene nucleation and Cu substrate. Herein, we report a layer-by-layer growth of large area graphene with precisely controlled number of layers and stacking order using a novel two-step two-heating zone low pressure chemical vapor deposition. The layered epi-growth on initially grown monolayer graphene limits the effect of underlying metal catalyst, thus leading to fully Bernal stacked bi-layer graphene as indicated by Raman spectra and electron diffraction patterns. Atomic resolution images with optical and electrical measurements verify the successful demonstration of the layer-by-layer synthesis by controlling growth time as a key parameter with other variables at their optimal process conditions.