Research Highlights

Correlative analysis on InGaN/GaN nanowires: structural and optical properties of self-assembled short-period superlattices

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 27 (2023)

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 InxGa1-xN regions with a period of 2–3 nm that are covered by a GaN shell and that transition to a more homogenous InxGa1-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.

Figure from the publication
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