物理化学学报 >> 2011, Vol. 27 >> Issue (07): 1615-1620.doi: 10.3866/PKU.WHXB20110729

理论与计算化学 上一篇    下一篇

Au掺杂硅纳米线的稳定性和电子结构

梁伟华, 王秀丽, 丁学成, 褚立志, 邓泽超, 傅广生, 王英龙   

  1. 河北大学物理科学与技术学院, 河北 保定 071002
  • 收稿日期:2011-02-21 修回日期:2011-04-29 发布日期:2011-06-28
  • 通讯作者: 王英龙 E-mail:hdwangyl@hbu. cn
  • 基金资助:

    国家自然科学基金(10774036)和河北省自然科学基金(E2008000631)资助项目

Stability and Electronic Structures of Au-Doped Silicon Nanowires

LIANG Wei-Hua, WANG Xiu-Li, DING Xue-Cheng, CHU Li-Zhi, DENG Ze-Chao, FU Guang-Sheng, WANG Ying-Long   

  1. College of Physics Science and Technology, Hebei University, Baoding 071002, Hebei Province, P. R. China
  • Received:2011-02-21 Revised:2011-04-29 Published:2011-06-28
  • Contact: WANG Ying-Long E-mail:hdwangyl@hbu. cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (10774036) and Natural Science Foundation of Hebei Province, China (E2008000631).

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摘要：

采用基于密度泛函理论的第一性原理的方法, 对Au掺杂[100]方向氢钝化硅纳米线(SiNWs)不同位置的形成能、能带结构、态密度及磁性进行了计算, 考虑了Au占据硅纳米线的替代、四面体间隙和六角形间隙的不同位置. 结果表明: Au偏爱硅纳米线中心的替代位置. Au掺杂后的硅纳米线引入了杂质能级, 禁带宽度变窄. 对于Au替代掺杂, 杂质能级主要来源于Au的d、p态和Si的p态, 由于Au的d态和Si的p态的耦合, Au掺杂硅纳米线具有铁磁性. 对于间隙掺杂, 杂质能级主要来源于Au的s态, 是非磁性的. 另外, 根据原子轨道和电子填充模型分析了其电子结构和磁性.

关键词: 硅纳米线, 第一性原理, 掺杂方式, 形成能, 态密度, 磁性

Abstract:

We calculated the formation energies, band structure, density of states, and magnetic properties of Au-doped hydrogen-passivated silicon nanowires (SiNWs) along the [100] direction at different positions by first-principles method based on density functional theory. We considered the substitutional positions, the interstitial positions with tetrahedral symmetry, and the interstitial positions with hexagonal symmetry. The results show that Au preferentially occupies the center substitutional position of the silicon nanowire. The doping of Au into silicon nanowires introduces an impurity level near the Fermi level. The bandgap values were less than those of pure silicon nanowires. For the substitutionally doping of silicon nanowires the density of states near the Fermi level were mainly contributed to by the Au d and p orbitals and the Si p orbital. Ferromagnetic behavior of the substitutionally doped nanowire was observed upon coupling the Au d and Si p states. For the interstitial doping of silicon nanowires nonmagnetic behavior was predicted. In addition, we also interpret the electronic and magnetic properties in terms of a simple analysis based on the atomic orbitals and electron filling.

Key words: Silicon nanowire, First-principles, Doping-method, Formation energy, Density of state, Magnetic property