第一性原理研究单个Si原子掺杂石墨烯结构的电子性质

Electronic Properties of Single Si At-om-Doped Graphene: A First Principle Study

摘要: 本文利用第一性原理对单个Si原子掺杂石墨烯结构的电子性质进行了计算模拟研究。结果表明，该体系的原子间杂化成键状态倾向于sp2-sp3混合杂化，原子排列出现了褶皱，石墨烯原有的空间反演对称性破缺，使得石墨烯能带结构中的狄拉克锥的零能隙打开。通过投影能带发现，掺杂Si原子在狄拉克锥附近的贡献较小，其主要影响是改变体系的杂化成键状态使体系几何结构发生改变，进而导致体系的电子性质发生变化。

Abstract: By using first principle calculations, we have investigated electronic properties of single Si atom doped graphene. The results showed that the atoms in this structure tend to bond in a sp2-sp3 mix-ing hybridization, and the atomic arrangement of this structure is predicted to be buckling. Hence, the inversion-symmetry of the whole system is broken, which results in opening a gap in the Dirac cone of the band structure for graphene. Through the analysis of projected band structure, we found that the doping Si atom is of little contribution around the Dirac cone. We predicted that the impact of the Si atom is to induce the change of hybridization states in this structure and then leads to the change of electronic properties.