【摘要】 采用基于密度泛函理论的赝势平面波方法,对掺入Mn,Cr,Co,Ni的β-FeSi2的几何结构、能带结构和光学性质进行了研究.计算结果表明:(1)杂质的掺入改变了晶胞体积及原子位置,掺杂是调制材料电子结构的有效方式;(2)系统总能量的计算表明Mn掺杂时倾向于置换FeI位的Fe原子,而Cr,Co,Ni倾向于取代FeII位的Fe原子;能带结构的计算表明掺Mn,Cr使得β-FeSi2的费米面向价带移动,形成了p型半导体;而掺Co,Ni则使得β-FeSi2的费米面向导带移动,形成了n型半导体;(3)杂质原子的掺入在费米面附近提供了大量的载流子,改变了电子在带间的跃迁,对β-FeSi2的光学性质造成影响.更多还原

【Abstract】 The electronic structure and optical properties of impurity(Mn,Cr,Co,Ni)-doped β-FeSi2 have been studied using the first principle plane-wave pseudo-potential based on the density function theory.The calculated results show that Mn prefers the FeI site,whereas Cr,Co,and Ni prefer the FeII site.The change about the volume and the atom position of the β-FeSi2 cell depends strongly on the species of dopants and the doped atom’s sites.The Fermi surface moves to the valence band with impurity from Mn or Cr and the β-FeSi2 becomes a p-type semiconductor while the Fermi surface moves to the conduction band with impurity from Co or Ni and the β-FeSi2 becomes a n-type semiconductor.The dopants can provide large numbers of carriers near the Fermi energy and change the properties of the interband transition of electrons.更多还原