Self-induced GaN nanowire growth: surface density determination

A new numerical approach for the determination of the GaN nanowire surface density on an AlN/Si substrate as a function of the growth time and gallium flux is presented. Within this approach, the GaN island solid-like coalescence and island-nanowire transition are modeled by the Monte-Carlo method. We show the importance of taking into consideration the island coalescence for explaining that the maximum of GaN island surface density is several times larger than the maximum of GaN nanowire surface density. Also, we find that the nanowire surface density decreases with an increase of the gallium flux.