First-principles study of B or Al-doping effect on the structural, electronic structure and magnetic properties of γ-graphyne

The structural, electronic structure and magnetic properties of B or Al-doped γ-graphyne are investigated by the first-principles calculations. The calculated results reveal that the B dopant has little effect on the geometrical structure of γ-graphyne. However, the Al dopant drastically changes the geometrical structure of γ-graphyne, rendering Al and its neighboring C atoms protrude from the γ-graphyne surface. Moreover, B doping introduces shallow acceptor levels near the top of the valence band, thus modifying the electronic properties by producing p-type behavior. But Al doping induces highly localized electronic states into the band gap, and the electrical activity of γ-graphyne is little changed. Meanwhile, the substitution of B or Al for C atom results in magnetic properties in γ-graphyne. A possible origin of the spin splitting character of doped γ-graphyne is proposed.