Ab initio study of the adsorption of Potassium on B, N, and BN-doped graphene heterostructure

Abstract The adsorption of Potassium atom on graphene doped with Nitride, Boron, and Boron nitride hexagons is studied using DFT with LDA and GGA for both spin and non-spin polarization calculations. The distortion in graphene resulting from Boron nitride doping is unnoticeable; alternatively, pure Boron and Nitrogen hexagons introduce high level of distortion in the layer. Adsorption energy, structural geometry, density of state, band structure, charge density, charge transfer, dipole moment and work function are calculated. For Boron and Nitrogen hexagons-doped graphene, the adsorption energy of Potassium increases dramatically compared to pristine graphene, but in the case of Boron nitride hexagons, calculations show weak adsorption energy of Potassium on the doped sheet. The doping of graphene with Boron nitride opens a small band gap, and the adsorption of Potassium rises the Fermi level above the opened gap leading to the formation of n-type semiconductor. Co-existence of partial covalent bond and ionic bond between Potassium and the doped graphene has been demonstrated. The transfer of charges is calculated in four different methods, one by using Bader analysis and the other three are based on DOS, average charge density difference and electric dipole moment.