Ga ∕ Au alloy catalyst for single crystal silicon-nanowire epitaxy

Abstract

Epitaxial growth of single crystalline silicon nanowires along the ⟨111⟩ directions was obtained on Si (100) and Si (111) substrates by gold-gallium-nanoparticle-catalyzed chemical vapor deposition with a SiH4 precursor. In comparison to the pure gold catalyst, the proportion of the nanowires growing perpendicular to the substrate is much higher and the wires show almost no kinks. The average diameter is smaller, and the diameter and length distributions are narrowly dispersed. By making a particular choice of growth conditions, it is possible to realize either rodlike or tapered silicon nanowires, which may be desirable for applications as field emitters.