Bandgap engineering of graphene by molecular conformation of trioxosumanene

Abstract Geometric and electronic structures of graphene adsorbing trioxosumanene (C 21 O 3 H 6 ) were investigated using the density functional theory concerning its molecular conformations. Graphene decreases the energy barrier for the bowl inversion reaction of trioxosumane owing to the substantial interaction between them. The trioxosumanene on graphene with the bowl-edge conformation opens the band gap in the Dirac cone at the Fermi level because the lowest unoccupied state of the trioxosumanene hybridizes with the electron states associated with the Dirac cone. In contrast, the graphene adsorbing trioxosumanene with the bowl-head conformation retains its characteristic band structure. Comprehensive calculations on other sumanene derivatives with the carbonyl group revealed that the derivatives with the deep lowest unoccupied state and without the steric hindrance for adsorption modulate the Dirac cone of graphene.