The effect of copper pretreatment on graphene synthesis by ion implantation into Ni/Cu substrate.

Synthesis of graphene on Ni/Cu bilayer substrate by ion implantation is sensitive to the quality of the Ni/Cu substrate. In this work, different pretreatments of Cu foils were implemented to elucidate the role of Cu pretreatment on graphene synthesis. Four types of pretreatments including polishing, annealing at 950 °C, annealing at 1000 °C, and annealing at 1050 °C were conducted prior to the growth of the Ni coating layer. Four different Ni/Cu substrates were implanted by carbon ions and annealed to obtain monolayer graphene. It shows that the impurity particles emerging on the Cu foils annealed at 1000 °C and 1050 °C affect the crystalline quality of the synthesized graphene. In addition, the increase in roughness due to the polishing process induces non-uniformity of the obtained graphene. Overall, annealing at 950 °C is proven to be the proper pretreatment for Cu foil, and the corresponding graphene film has excellent crystalline quality and uniformity compared to those obtained on the substrates with other pretreatments. [ABSTRACT FROM AUTHOR]