Spin-polarized bandgap of graphene induced by alternative chemisorption with MgO (1 1 1) substrate

Using First-principle calculations, the substrate effect of O-terminated ( 3 × 3 ) MgO (1 1 1) on graphene was investigated for spintronics application. It was found that the graphene could be turned into a spin-polarized semiconductor due to alternative sp3 chemisorption with the substrate. The majority spin channel has an insulating band gap of 2 eV, while the minority spin channel has a semiconducting band gap of 0.3 eV. These results imply that the graphene with a tailored pattern of chemisorption could be highly efficient for introducing a totally spin-polarized current and controlling its on/off switching.