Self-regulated radius of spontaneously formed GaN nanowires in molecular beam epitaxy

Abstract

We investigate the axial and radial growth of GaN nanowires upon a variation of the Ga flux during molecular beam epitaxial growth. An increase in the Ga flux promotes radial growth without affecting the axial growth rate. In contrast, a decrease in the Ga flux reduces the axial growth rate without any change in the radius. These results are explained by a kinetic growth model that accounts for both the diffusion of Ga adatoms along the side facets towards the nanowire tip and the finite amount of active N available for the growth. The model explains the formation of a new equilibrium nanowire radius after increasing the Ga flux and provides an explanation for two well known but so far not understood experimental facts: the necessity of effectively N-rich conditions for the spontaneous growth of GaN nanowires and the increase in nanowire radius with increasing III/V flux ratios.

References in corpus (5)

• Why does wurtzite form in nanowires of III-V zinc-blende semiconductors?
• A growth diagram for plasma-assisted molecular beam epitaxy of GaN nanocolumns on Si(111)
• Spontaneous nucleation and growth of GaN nanowires: Fundamental role of crystal polarity
• In situ investigation of growth modes during plasma-assisted molecular beam epitaxy of (0001)GaN
• Compared growth mechanisms of Zn-polar ZnO nanowires on O-polar ZnO and on sapphire

Cited by in corpus (10)

• Molecular Beam Epitaxy of GaN Nanowires on Epitaxial Graphene
• Monitoring the formation of nanowires by line-of-sight quadrupole mass spectrometry: a comprehensive description of the temporal evolution of GaN nanowire ensembles
• Correlation between the structural and optical properties of spontaneously formed GaN nanowires: a quantitative evaluation of the impact of nanowire coalescence
• High-temperature growth of GaN nanowires by molecular beam epitaxy: toward the materials quality of bulk GaN
• Investigating the origin of the nonradiative decay of bound excitons in GaN nanowires
• Self-Assembled formation of long, thin, and uncoalesced GaN nanowires on crystalline TiN films
• Compatibility of the selective area growth of GaN nanowires on AlN-buffered Si substrates with the operation of light emitting diodes
• Polarity-induced selective area epitaxy of GaN nanowires
• Elastic vs. plastic strain relaxation in coalesced GaN nanowires: an x-ray diffraction study
• Localization and defects in axial (In,Ga)N/GaN nanowire heterostructures investigated by spatially-resolved luminescence spectroscopy