title: Impact of nucleation conditions on diameter modulation of GaAs nanowires.
abstract: Diameter-modulated nanowires can be used to impart unique properties to nanowire-based devices. Here, diameter modulation along Au-seeded GaAs nanowires was achieved by varying the flux of the III and V precursors during growth. Furthermore, three different types of [111]B-oriented nanowires were observed to display distinct differences in diameter modulation, growth rate, and cross-sectional shape. These differences are attributed to the presence of multiple distinct Au-Ga seed particle phases at the growth temperature of 420 °C. We show that the diameter modulation behavior can be modified by the growth conditions during nanowire nucleation, including temperature, V/III ratio, substrate orientation, and seed particle size. These results demonstrate the general viability of flow-controlled diameter modulation for compound semiconductors and highlight both opportunities and challenges that can arise from using compound-forming alloys to seed nanowire growth.
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Samuel C
authors.initials: SC
authors.lastname: Crawford
authors.forename: Sema
authors.initials: S
authors.lastname: Ermez
authors.forename: Georg
authors.initials: G
authors.lastname: Haberfehlner
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Jones
authors.forename: Silvija
authors.initials: S
authors.lastname: Gradečak