Graphene Exfoliation from HOPG Using the Difference in Binding Energy between Graphite, Graphene and a Substrate

Abstract

Since its discovery in 2004, the graphene global market had a huge/considerable growth. Such growth can be explained by the use of graphene in specific or targeted applications where it has a huge and clear advantage. Although graphene is growing and has many possible applications, its market fraction is insignificant compared to the carbon global market. This is simply explained because the industry still has challenges related to quality, costs, reproducibility and safety. In this chapter, we propose a new look on the mechanical exfoliation. Basically, based on the difference in binding energy between graphite, graphene and a substrate we can exfoliate. The binding energy is the energy between materials at equilibrium. When 3 materials A-B-C are interacting, if the binding energy between A-B is superior to B-C, then by moving A in the opposite direction, B will follow. Based on that, we calculated the interaction potential between graphite, graphene and a substrate using the standard Lennard-Jones potential. Conventional substrates like silicon and silicon dioxide cannot exfoliate while gold, silver and copper can at 3.2 to 3.3 Å. This difference may be because of their higher atomic density and modest lattice parameter compared to others substrates used in this study.