氧钝化石墨纳米带电子和光学性质的第一性原理

Electronic and Optical Properties of O-Terminated Armchair Graphene Nanoribbons

采用第一性原理方法，研究了氧原子钝化的扶手椅型石墨纳米带的结构、电磁特性和光学性质．氧原子钝化的石墨纳米带比氢原子钝化稳定，显示出金属性质．自旋极化计算的能带和态密度研究表明，该纳米带反铁磁态比铁磁态稳定，表现为反铁磁半导体特征．由于边沿钝化的氧原子的影响，该系统的介电函数有明显的红移，且第一个介电峰主要由最高价带贡献．介电函数、折射系数、吸收系数及能量损失等的峰值与电子跃迁吸收有关．

The structure, electromagnetic and optical properties of the O-terminated graphene nanorib- bons with armchair edge are studied using first-principles theory. The results show that the O-terminated armchair edge are more stable than the H-terminated ribbons and show metal- lic character. Spin-polarized calculations reveal that the antiferromagnetic state are more stable than the ferromagnetic state. The energy band and density of states analyses show that the O-terminated armchair edge are antiferromagnetic semiconductors. Because of the terminated 0 atoms, the dielectric function has an evident red shift and the first peak is the strongest with its main contribution derived from the highest valence band. The peaks of the dielectric function, reflection, absorption, energy loss are related to the transition of electrons. Our results suggest that the O-terminated graphene nanoribbons have potential applications in nanoelectronics, opto-electric devices.