▎ 摘　　要

The effects of torsional deformation on the structural stability, the electronic structures and the optical properties, including adsorption energy, band gap, absorption coefficient and reflectivity of O atom adsorbed graphene are studied by using the first-principles calculations. Our results indicate that the C atom closest to O atom is pulled up, causing the graphene plane to be distorted after the O atom has been adsorbed. The adsorption energy calculations show that due to the adsorption of O atom, the structural stability of graphene system decreases, but the degree of torsion has a weak effect on the structural stability. The analysis of band structure shows that the adsorption of O atom causes the graphene to convert into a semiconductor from a metal. Torsional deformation makes it change from a semiconductor to a metal, and to a semiconductor. The O atom adsorption system with a torsion angle of 12 degrees has an indirect band gap but the band gaps of other systems are all direct bandgaps. Compared with the intrinsic graphene torsion system, the adsorbed O atom system has an electronic structure that is less sensitive to torsional deformation. When the torsion angle changes from 10 degrees to 16 degrees, the bandgap is always stable at around 0.11 eV. And the adsorption system always corresponds to a narrow bandgap semiconductor in this torsion angle range. For optical properties, comparing with the O atoms adsorbed on graphene with the 0 degrees torsion angle, the peaks of the absorption coefficient and the reflectivity of the system are reduced, and have a transform of red shift into blue shift in a torsion angle ranging from 2 degrees to 20 degrees.