Gold catalyst initiated growth of GaN nanowires by MOCVD

J. P. Ahl, H. Behmenburg, C. Giesen, I. Regolin, W. Prost, F. J. Tegude, G. Z. Radnoczi, B. Pécz, H. Kalisch, R. H. Jansen, M. Heuken

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Abstract

Our study shows the impact of the process parameters V/III ratio, pressure and temperature on growth and morphology of GaN nanowires (NWs) synthesized by an Au-initiated vapour-liquid-solid mechanism on a sapphire substrate. We confined a temperature window for successful GaN NW growth and show how the variation of reactor pressure changes the NW morphology. Using a very low V/III ratio, NW tapering, which was observed for higher V/III ratios, could be avoided. The optimization of these process parameters led to non-tapered GaN NWs, aligned perpendicular to the substrate. Further evaluation by scanning electron microscopy showed a high density (~3·109/cm2) of hexagonal c-plane GaN NWs having diameters of 60 ± 9 nm. Transmission electron microscopy revealed single-crystalline NWs without threading dislocations but some stacking faults. The use of a very low V/III ratio was found to be important for the successful selective growth and, most interestingly, led to a difference in NW and gold catalyst droplet diameter. For chemical analysis of the NW and its catalyst droplet, electron energy loss spectroscopy was employed confirming gold as the catalyst material.

Original languageEnglish
Pages (from-to)2315-2317
Number of pages3
JournalPhysica Status Solidi (C) Current Topics in Solid State Physics
Volume8
Issue number7-8
DOIs
Publication statusPublished - Jul 1 2011

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Keywords

  • Au catalyst
  • GaN
  • MOCVD
  • Nanowire
  • VLS

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Ahl, J. P., Behmenburg, H., Giesen, C., Regolin, I., Prost, W., Tegude, F. J., Radnoczi, G. Z., Pécz, B., Kalisch, H., Jansen, R. H., & Heuken, M. (2011). Gold catalyst initiated growth of GaN nanowires by MOCVD. Physica Status Solidi (C) Current Topics in Solid State Physics, 8(7-8), 2315-2317. https://doi.org/10.1002/pssc.201000992