Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (07): 1615-1620.doi: 10.3866/PKU.WHXB20110729

• THEORETICAL AND COMPUTATIONAL CHEMISTRY • Previous Articles     Next Articles

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).

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

MSC2000: 

  • O641