薁缺陷对螺旋石墨烯纳米带二阶非线性光学性质调制的理论研究

his paper uses theoretical simulation to find nonlinear optical materials with good nonlinear optical response. Because the spiral graphene nanoribbons have unique helicity, unique chirality, and some excellent properties of graphene, the central symmetry of the spiral graphene nanoribbons (HGN) is changed by the introduction of azulene defects. It is expected to be a nonlinear optical material with good nonlinear optical response. The AHGN-a structure with good kinetic stability and high first hyperpolarizability was obtained by the ZINDO-SOS method. For example, the first hyperpolarizability at the length of twelve unit is 1616.46×10-30esu (5.57×10-30esu /heavy-atom) and finding out the arrangement of azulene defects is the main factor determining the first hyperpolarizability, and the amount of doping also plays a role that cannot be ignored. In addition, the causes of the first hyperpolarizability of AHGN-a were discussed in detail by means of electronic spectroscopy, frontier molecular orbitals, and so on. The second-order nonlinear optical response process of AHGN-a in different external fields is predicted and characterized by two-dimensional second order nonlinear optical spectrum.