Impact of nucleation conditions on diameter modulation of GaAs nanowires

TitleImpact of nucleation conditions on diameter modulation of GaAs nanowires
Publication TypeJournal Article
Year of Publication2015
AuthorsCrawford, SC, Ermez, S, Haberfehlner, G, Jones, EJ, Gradecak, S
Date Published2015/06/05/

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 degrees 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.