On the growth of InGaN nanowires by molecular-beam epitaxy: influence of the III/V flux ratio on the structural and optical properties

In this work, we studied the influence of the III/V flux ratio on the structural and optical properties of InGaN nanowires grown by plasma-assisted molecular beam epitaxy. It was found that the formation of InGaN nanowires with a core–shell structure occurs if the III/V flux ratio is about 0.9–1.2 taking into account the In incorporation coefficient. At the same time, an increase in the III/V flux ratio from the intermediate growth regime to metal-rich one leads to a decrease in the In content in nanowires from ~45% to ~35%. This nanowires exhibit photoluminescence at room temperature with a maximum in the range of 600–650 nm. A further increase in the III/V flux ratio to ~1.3, or its decrease to ~0.4 leads to the formation of coalesced nanocolumnar layers with a low In content. The results obtained may be of interest for studying the growth processes of InGaN nanowires and creating RGB light-emitting devices on them.