Growth of n-type InGaN nanorods on p-type silicon substrates dependent on III/V ratio

We have grown n-type InGaN nanorods directly on p-type Si substrates with a varying group III flux, by using plasma-assisted molecular beam epitaxy technique. The crystal structure was studied by measuring reflection high-energy electron diffraction patterns while the morphological and optical properties of the InGaN nanorods were investigated by using scanning electron microscope images and room temperature photoluminescence spectra. The photoluminescence band-to-band peak was shifted to a lower energy position by increasing group-III flux due to increased In concentration in the InGaN nanorod structure. Under optimal growth conditions, uniform indium concentration up to 36% was achieved without any evidence of phase separation, In droplet or optically observed defects.