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

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

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.
Published in: Discover Nano, 10.1186/s11671-023-03808-6, Springer Nature