Au掺杂浓度对Si纳米线电子结构和磁性的影响

利用基于密度泛函理论的第一性原理,对不同直径和浓度Au掺杂Si纳米线的态密度和磁性进行了计算。结果表明:杂质Au的形成能随Si纳米线直径的增大和掺杂浓度的降低而下降,这说明直径越小的Si纳米线掺杂越困难,杂质浓度越高的Si纳米线越不稳定。其磁性是由于Au d轨道和Si p轨道的p-d耦合而产生的;改变Au的掺杂浓度可改变Si纳米线的带隙,也改变了其磁矩的大小。

Effects of Au Doping Concentration on the Electronic Structure and Magnetic Properties of Si Nanowires

The density of states and magnetic properties for Au-doped Si nanowires with different diameters and concentration were calculated by first-principles based on density functional theory.The results show that the formation energies of Au impurity decrease as both the diameters of Si nanowires increase and impurity concentration of Si nanowires decrease.The results indicated that doping in smaller diameter Si nanowires is difficult and higher impurity concentrations in Si nanowires are unstable.A ferromagnetic behavior of its is derived from coupling of Au d and Si p states.The change of Au-doped concentration can result in the change in the band gap of Si nanowire and improvement of its magnetic moment.