Catalyst shape engineering for anisotropic cross-sectioned nanowire growth.

ABSTRACT: The ability to engineer material properties at the nanoscale is a crucial prerequisite for nanotechnology. Hereunder, we suggest and demonstrate a novel approach to realize non-hemispherically shaped nanowire catalysts, subsequently used to grow InP nanowires with a cross section anisotropy ratio of up to 1:1.8. Gold was deposited inside high aspect ratio nanotrenches in a 5?nm thick SiN_x selective area mask; inside the growth chamber, upon heating to 455?°C, the thin gold stripes agglomerated, resulting in an ellipsoidal dome (hemiellipsoid). The initial shape of the catalyst was preserved during growth to realize asymmetrically cross-sectioned nanowires. Moreover, the crystalline nature of the nanowire side facets was found to depend on the nano-trench orientation atop the substrate, resulting in hexagonal or octagonal cross-sections when the nano-trenches are aligned or misaligned with the [1?10] orientation atop a [111]B substrate. These results establish the role of catalyst shape as a unique tool to engineer nanowire growth, potentially allowing further control over its physical properties.

SUBMITTER: Calahorra Y 

PROVIDER: S-EPMC5247733 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature