Chemical bonding-dominated energy gap in graphene oxides
Tran Ngoc Thanh Thuy1*, Lin Ming-Fa1
1Physics, National Cheng Kung University, Tainan, Taiwan
* presenting author:Ngoc Thanh Thuy Tran,
Electronic properties of graphene oxides are investigated using first-principle calculations. They are very sensitive to the changes in the oxygen concentration and distribution, especially the energy gap. The feature-rich band structures exhibit the destruction or distortion of the Dirac cone, opening of band gap, O- and (C,O)-dominated energy dispersions, and extra critical points. The orbital-projected density of states (DOS) have many special structures mainly coming from a composite energy band, the parabolic and partially flat ones. The DOS and spatial charge distributions clearly indicate the critical orbital hybridizations in O-O, C-O and C-C bonds. The band decomposed charge distributions reveal the p-bonding at some specific k-points, being responsible for the energy gap.

Keywords: graphene oxides, chemical bonding, band gap, density of states, charge density