(Invited) Doping, Functionalization, and Permeability of Graphene: Insights from First-Principles Studies

Even though graphene is exceptional with respect to several physical properties, its use in electronic devices requires modification of the material. For example, development of graphene-based transistors necessitates the controlled increase of the number of charge carriers. Other applications may employ graphene chemical derivatives with enhanced functionalities. Here we review results from recent density-functional theory (DFT) studies on key processes that could dope or functionalize graphene. We demonstrate the crucial role carbon vacancies (single vacancies or double vacancies) can play in enabling substitutional doping and describe a vacancy-free doping scheme that employs the physisorption of ammonium groups. Finally, we show that graphene may be selectively permeable to certain atomic species, for example boron atoms.