Correlated nanoscale analysis of the emission from wurtzite versus zincblende (In,Ga)As/GaAs nanowire core-shell quantum wells

Jonas Lähnemann*, Megan O. Hill, Jesús Herranz, Oliver Marquardt, Guanhui Gao, Ali Al Hassan, Arman Davtyan, Stephan O. Hruszkewycz, Martin V. Holt, Chunyi Huang, Irene Calvo-Almazán, Uwe Jahn, Ullrich Pietsch, Lincoln J. Lauhon, Lutz Geelhaar

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

While the properties of wurtzite GaAs have been extensively studied during the past decade, little is known about the influence of the crystal polytype on ternary (In,Ga)As quantum well structures. We address this question with a unique combination of correlated, spatially resolved measurement techniques on core-shell nanowires that contain extended segments of both the zincblende and wurtzite polytypes. Cathodoluminescence hyperspectral imaging reveals a blue-shift of the quantum well emission energy by 75 ± 15 meV in the wurtzite polytype segment. Nanoprobe X-ray diffraction and atom probe tomography enable k·p calculations for the specific sample geometry to reveal two comparable contributions to this shift. First, there is a 30% drop in In mole fraction going from the zincblende to the wurtzite segment. Second, the quantum well is under compressive strain, which has a much stronger impact on the hole ground state in the wurtzite than in the zincblende segment. Our results highlight the role of the crystal structure in tuning the emission of (In,Ga)As quantum wells and pave the way to exploit the possibilities of three-dimensional band gap engineering in core-shell nanowire heterostructures. At the same time, we have demonstrated an advanced characterization toolkit for the investigation of semiconductor nanostructures.

Original languageEnglish (US)
Pages (from-to)4448-4457
Number of pages10
JournalNano letters
Volume19
Issue number7
DOIs
StatePublished - Jul 10 2019

Keywords

  • (In,Ga)As quantum well
  • Nanowire
  • atom probe tomography
  • cathodoluminescence
  • nanofocused X-ray diffraction
  • polytype

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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