Models for various arrangements of oxygen atoms on the graphene sheet with the coverage of (a) 50% , (b) 25% , (c) 16.7% , and (d) 12.5% . The black dots and gray spheres represent carbon and oxygen atoms, respectively. The dashed lines show the unit cells for the corresponding models.
Band structures of (a) the simple graphene sheet, (b) the oxygen-adsorbed graphene (16.7%), and (c) the oxygen-adsorbed graphene (50%). The nsets show the BZs for the corresponding systems.
Optimized lattice constant of (a) the oxygen-adsorbed graphene as a function of and (b) its dependency on added electrons into the system.
Probability density of (a) the highest occupied state of the valence band for the graphene sheet at the point and (b) that for the oxygen-adsorbed graphene (50%), which are drawn in a plane perpendicular to the graphene sheet (dashed lines in the top view). The black and gray circles show carbon and oxygen atoms, respectively.
(a) Adsorption energy as a function of . (b) shows a migration potential surface of oxygen atoms on the graphene sheet for the coverages of 16.7%. “(1)” and “(2)” in (b) represent equivalent bridge sites on the graphene sheet. The arrow shows a migration path between the bridge sites schematically. The energy for the most stable site is set to be zero.
Energy gap for the models employed.
Article metrics loading...
Full text loading...