▎ 摘　　要

First-principle calculations are used to study the electronic structures, electronic and optical properties of pure, phosphorus-doped, aluminum-doped, and phosphorus and aluminum co-doped graphene. The gap between the conduction band and valence band of intrinsic graphene is zero. However, when graphene is doped with P, Ga, and P-Ga, the gap in energy will be opened and to a different extent. In the three different doping results, the gap values between the conduction and valence bands of P, Ga, and P-Ga graphene are 0.11, 0.35, and 0.39 eV, respectively. When graphene is doped with P-Ga, more electrons (1.40 e) will be gained by carbon atoms compared to P-doped graphene (0.61 e), while fewer electrons (1.49 e) will be transferred to carbon atoms compared to Ga-doped graphene (1.75 e). After doping with P, Ga, and P-Ga, the overall intensity of the graphene absorption peak is weakened and more pronounced relative to the low-frequency peaks. This result can fully demonstrate that the band gap of the doped graphene system can be better tuned by adding phosphorus and gallium atoms.