Manuel Alonso‑Orts, Rudolfo Hötzel, Tim Grieb, Matthias Auf der Maur, Maximilian Ries, Felix Nippert, Benjamin März, Knut Müller‑Caspary, Markus R. Wagner, Andreas Rosenauer, Martin Eickhoff

DiscoverNano 18 (2023): 27

https://doi.org/10.1186/s11671-023-03808-6

The influence of self-assembled short-period superlattices (SPSLs) on the structural and optical properties of InGaN/GaN nanowires (NWs) grown by PAMBE on Si (111) was investigated by STEM, EDXS, µ-PL analysis and k·p simulations. STEM analysis on single NWs indicates that in most of the studied nanostructures, SPSLs self-assemble during growth. The SPSLs display short-range ordering of In-rich and In-poor In_xGa_1-xN regions with a period of 2–3 nm that are covered by a GaN shell and that transition to a more homogenous In_xGa_1-xN core. Polarization- and temperature-resolved PL analysis performed on the same NWs shows that they exhibit a strong parallel polarized red-yellow emission and a predominantly perpendicular polarized blue emission, which are ascribed to different In-rich regions in the nanostructures. The correlation between STEM, µ-PL and k·p simulations provides better understanding of the rich optical emission of complex III-N nanostructures and how they are impacted by structural properties, yielding the significant impact of strain on self-assembly and spectral emission.