In Desorption in InGaN Nanowire Growth on Si Generates a Unique Light Emitter: From In-Rich InGaN to the Intermediate Core–Shell InGaN to Pure GaN

Abstract

High Resolution Image Download MS PowerPoint Slide We study the desorption of In in InGaN nanowire (NW) growth on Si, generating a unique light emitter. With increasing growth temperature above the onset of In desorption, uniform, In-rich InGaN NWs evolve into the intermediate core–shell InGaN NW structures with In-rich core and In-poor shell before the In-rich core is dissolved and pure GaN NWs are left. The different InGaN NW structures are characterized by X-ray diffraction (XRD), photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) spectroscopy. A growth model is developed to understand the distinct growth regimes by the interplay of anisotropic In surface diffusion and In desorption on the m-plane NW sidewalls and the c-plane NW top. The self-formed core–shell InGaN NWs are identified as the active region of our InGaN red light-emitting diode.