Tuneable molecular doping of corrugated graphene

Density functional theory (DFT) modeling of the physisorption of four different types of molecules (toluene, bromine dimmer, water and nitrogen dioxide) over and under graphene ripples has been performed. For all types of molecules changes of charge transfer and binding energies in respect to flat graphene are found. The changes in the electronic structure of corrugated graphene and turn of π-orbitals of carbon atoms in combination with the chemical structure of adsorbed molecules are proposed as the causes of difference with the perfect graphene case and variety of adsorption properties of different types of molecules. The results of calculation suggest that the tops of the ripples are more attractive for large molecules and valley between ripples for small molecules. Stability of molecules on the ripples and energy barriers for migration over flat and corrugated graphene is also discussed.