▎ 摘　　要

The effect of electric field on electronic properties of defect-free and defective bilayer graphene is studied using density functional theory. The results indicate that the defect-free bilayer graphene exhibits semi-metallic properties. We considered the most topological defect, known as Stone-Wales defect in grapheme layers. The defect breaks the symmetry substantially and makes the defective bilayer graphene as semiconductor. The band structures of defect-free and defective bilayer graphene are changed, and a gap between bands is observed by applying an electric field perpendicular to the layers. It was found that the band gap enhances with increasing of the electric field.