Group V sensitive vapor–liquid–solid growth of Au-catalyzed and self-catalyzed III–V nanowires

• Analytical approach is proposed for describing the VLS growth of III–V nanowires.
• The transition from transport to nucleation limited VLS growth is demonstrated.
• Radial growth or self-equilibration in Ga-catalyzed GaAs nanowires is investigated.
• The model correlates well with recent experimental findings and numerical models.

We present a new theoretical model that treats the group V sensitive growth rates and structures of Au-catalyzed and self-catalyzed III–V nanowires within a single kinetic picture. It is shown that Au-catalyzed III–V nanowires can grow with a time-independent radius within a wide range of parameters. At high V/III flux ratios, the vapor–liquid–solid growth of Au catalyzed III–V nanowires is controlled by surface diffusion of the group III adatoms, while at low V/III flux ratios it becomes nucleation-limited. Conversely, self-catalyzed III–V nanowires cannot grow with a time-independent droplet size and instead such nanowires may either swell or shrink or converge to a certain stationary radius depending on the V/III flux ratio. Quite importantly, the results are presented in a concise analytical form which is convenient for comparison with experimental data or prior theoretical works. We demonstrate how the model fits the data obtained previously for Au- and Ga-catalyzed GaAs nanowires.