Relationship between planar GaAs nanowire growth direction and substrate orientation.

Planar GaAs nanowires are epitaxially grown on GaAs substrates of various orientations, via the Au-catalyzed vapor-liquid-solid mechanism using metal organic chemical vapor deposition. The nanowire geometry and growth direction are examined using scanning electron microscopy and x-ray microdiffraction. A hypothesis relating the planar nanowire growth direction to the surface projections of [111] B crystal directions is proposed. GaAs planar nanowire growth on vicinal substrates is performed to test this hypothesis. Good agreement between the experimental results and the projection model is found.