Control over the Number Density and Diameter of GaAs
Nanowires on Si(111) Mediated by Droplet Epitaxy
- Publication date
- Publisher
Abstract
We
present a novel approach for the growth of GaAs nanowires (NWs) with
controllable number density and diameter, which consists of the combination
between droplet epitaxy (DE) and self-assisted NW growth. In our method,
GaAs islands are initially formed on Si(111) by DE and, subsequently,
GaAs NWs are selectively grown on their top facet, which acts as a
nucleation site. By DE, we can successfully tailor the number density
and diameter of the template of initial GaAs islands and the same
degree of control is transferred to the final GaAs NWs. We show how,
by a suitable choice of V/III flux ratio, a single NW can be accommodated
on top of each GaAs base island. By transmission electron microscopy,
as well as cathodo- and photoluminescence spectroscopy, we confirmed
the high structural and optical quality of GaAs NWs grown by our method.
We believe that this combined approach can be more generally applied
to the fabrication of different homo- or heteroepitaxial NWs, nucleated
on the top of predefined islands obtained by DE