First-principles study of the IVA group atoms adsorption on graphene

The adsorption of five different IVA group atoms on graphene is studied by using the density functional theory. The adsorption energy, geometric, and electronic structure are calculated. We find that the adsorption energy decreases when the atomic number of adsorbate increases. The interaction between the adsorbate and graphene also changes from the strong covalent bond to the weak van der Waals interaction from C to Pb. For C and Si atoms, the stablest adsorption site is the bridge site, while for Ge, Sn, and Pb atoms, both the top and bridge sites are same stable. The spin-polarized calculations show that graphene could be magnetic when the IVA group atom adsorbed on it. Detailed analysis shows that the magnetic moment comes from the localized p orbital of IVA group atom.