Role of Ga-flux in Indium Incorporation and Emission Properties of Self-Assembled InGaN Nanowires Grown on Si (111)

We investigated the role of Ga-flux in determining the growth rate, emission spectra, and defect saturation properties of InGaN nanowires, keeping the growth conditions under a constant In-rich regime. The growth rate of the nanowires varied from 1.26 nm/min to 7.8 nm/min, following a near-proportional relationship with Ga-flux. The indium concentration in the wires increased with increased gallium flux at lower fluxes. This value peaked at higher gallium fluxes and decreased slowly afterward. This trend was justified by a phenomenological explanation using basic growth equations. It was established that the decomposition of In-N bonds plays a crucial role in controlling indium concentration under these conditions. Our results also suggested that Ga-flux impacts the recombination properties in these samples, with higher Ga-flux enhancing radiative recombination.