Growth of Three-Dimensional InGaN Nanostructures by Plasma-Assisted Molecular Beam Epitaxy.

A study on the formation of InGaN ternary compounds in the three-dimensional growth mode is presented. For the first time, we demonstrate that the self-organization during InGaN growth is responsible for the formation of core–shell nanowires (NWs), nanotubes, zinc blende (ZB) phases, and nanoflowers. It is found that the core–shell InGaN NWs are formed at the very initial stage of growth. An increase in growth time results in the ascending indium diffusion from the cores of NWs and their accumulation at the NW tips, enabling three-dimensional lateral growth and formation of nanotubes. Further nanostructure growth leads to the formation of nanoflowers with empty stems and ZB/wurtzite (WZ) phase interface at the periphery. The observed structural transformations of NWs are supported by transmission electron microscopy and photoluminescence measurements, as well as theoretical estimates. Understanding the formation mechanisms of these complex three-dimensional nanostructures can facilitate the development of InGaN compounds for gas-sensing applications. [ABSTRACT FROM AUTHOR]