Adjusting the electronic properties of silicon carbide nanoribbons by introducing edge functionalization

The structural and electronic properties of silicon carbide nanoribbons (SiC NRs) with edges passivated by hydrogen and halogens are calculated based on density functional theory. It is found that the band gap (Eg) values of armchair SiC NRs decrease as the atomic number of hydrogen and halogen elements increases. However the effect of edge functionalization on the Eg of zigzag SiC NRs is very small. This is because the energy levels of the conduction band minimum of armchair SiC NRs shift to lower energy by introducing hydrogen and halogen atoms, while the energies of the valence band maximum are barely affected. Our results provide a theoretical guideline to adjust the electronic properties of SiC NRs.