Author Description

Understanding the structural and electronic properties of graphene is one of the major areas of focus in materials science research. The electronic properties of graphene can be altered by chemical manipulations such as doping and adsorption of impurities, therefore understanding the mechanism and energetics of doping and adsorption has a crucial role in modifying the electronic properties of graphene. In this work, using the density functional theory, we calculate the doping formation energy and adsorption energy as a function of system size and pseudopotential. We find that the adsorption energy of graphene remains constant as a function of system size. Furthermore, we observe a switch in semiconducting behavior of graphene (say from p- to n-type) when an impurity atom is added as a dopant instead of added an adsorbent on the surface of a graphene sheet. In addition, we find that N and B doped graphene flips it's semiconducting behavior when adsorbed on graphene while O and Be show pristine-like behavior when adsorbed. Be-adsorbed graphene behaves like pure graphene because it gets adsorbed far above the graphene plane, making the interactions between graphene and Be negligible. Finally, this work clarifies the underlying reasons for large quantitative and qualitative inconsistencies in literature in terms of structural and electronic properties of graphene predicted from electronic structure calculations.