Periodic nanostructure arrays on Si(111) and Si(100) studied by scanning tunneling microscopy and first-principles theoretical calculation*

Qikun XUE and Jinfeng JIA

State Key Laboratory for Surface Physics and International Center of Quantum Structure, Institute of Physics, Chinese Academy of Sciences, China

A method to fabricate periodic metal nanowires/nanodots arrays by molecular beam epitaxy is described. The main strategy is to make use of the impurity-induced nanostructured Si(001)-2xn surface and the clean Si(111)-7x7 surface to control the nucleation process, which result in periodic spatial arrangements of the nanostructures grown. The atomic structure and stability of these nanowires and nanodots are studied by atomically resolved scanning tunneling microscopy images and first-principles total-energy calculations. The applicability of this strategy is demonstrated with different metals (Al, Ga and In), which provides a simple method for spontaneous fabrication of various metal nanostructure arrays with tunable sizes, compositions and spatial periodicities.

*The work was done in collaboration with Zhi-Qiang Li, John S. Tse at National Research Council of Canada and Zhenyu Zhang at Oak Ridge National Laboratory, USA.