▎ 摘　　要

Density functional theory calculations with van der Waals (vdW) correction were used to investigate the structural and electronic properties of monolayer and bilayer of partially chlorinated graphene (C4Cl); the effects of biaxial strain and external electric field (E-field) on the electronic structure of C4Cl nanosheets were also examined. The C4Cl monolayer is a semiconductor with an indirect bandgap of 1.51 eV. Interestingly, the weak vdW interactions between two C4Cl monolayers induce a much smaller bandgap in C4Cl bilayer than that in the single monolayer. More interestingly, the electronic structure of C4Cl monolayer and bilayer can be feasibly modulated by applying an external E-field and a biaxial strain, and the modulation can even result in semiconductor-metal transition. These findings present very interesting possibilities for tailoring the electronic properties of C4Cl nanosheets for future electronic devices.