3D Bragg Coherent Diffraction Imaging of Extended Nanowires: Defect Formation in Highly Strained InGaAs Quantum Wells

Megan O. Hill, Paul Schmiedeke, Chunyi Huang, Siddharth Maddali, Xiaobing Hu, Stephan O. Hruszkewycz, Jonathan J. Finley, Gregor Koblmüller*, Lincoln J. Lauhon*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

InGaAs quantum wells embedded in GaAs nanowires can serve as compact near-infrared emitters for direct integration onto Si complementary metal oxide semiconductor technology. While the core-shell geometry in principle allows for a greater tuning of composition and emission, especially farther into the infrared, the practical limits of elastic strain accommodation in quantum wells on multifaceted nanowires have not been established. One barrier to progress is the difficulty of directly comparing the emission characteristics and the precise microstructure of a single nanowire. Here we report an approach to correlating quantum well morphology, strain, defects, and emission to understand the limits of elastic strain accommodation in nanowire quantum wells specific to their geometry. We realize full 3D Bragg coherent diffraction imaging (BCDI) of intact quantum wells on vertically oriented epitaxial nanowires, which enables direct correlation with single-nanowire photoluminescence. By growing In0.2Ga0.8As quantum wells of distinct thicknesses on different facets of the same nanowire, we identified the critical thickness at which defects are nucleated. A correlation with a traditional transmission electron microscopy analysis confirms that BCDI can image the extended structure of defects. Finite element simulations of electron and hole states explain the emission characteristics arising from strained and partially relaxed regions. This approach, imaging the 3D strain and microstructure of intact nanowire core-shell structures with application-relevant dimensions, can aid the development of predictive models that enable the design of new compact infrared emitters.

Original languageEnglish (US)
Pages (from-to)20281-20293
Number of pages13
JournalACS nano
Volume16
Issue number12
DOIs
StatePublished - Dec 27 2022

Keywords

  • Bragg coherent diffraction imaging (BCDI)
  • III-V semiconductors
  • defects
  • nanowires
  • photoluminescence
  • quantum well

ASJC Scopus subject areas

  • Engineering(all)
  • Physics and Astronomy(all)
  • Materials Science(all)

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