Growth of GaN micro- and nanorods on graphene-covered sapphire: Enabling conductivity to semiconductor nanostructures on insulating substrates

Heilmann M, Sarau G, Göbelt M, Latzel M, Sadhujan S, Tessarek C, Christiansen S (2015)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2015

Journal

Crystal Growth and Design American Chemical Society

Publisher: American Chemical Society

Book Volume: 15

Pages Range: 2079-2086

Journal Issue: 5

DOI: 10.1021/cg5015219

Abstract

The self-catalyzed growth of vertically aligned and hexagonally shaped GaN micro- and nanorods on graphene transferred onto sapphire is achieved through metal-organic vapor phase epitaxy. However, a great influence of the underlying substrate is evident, since vertically aligned structures with a regular shape could not be grown on graphene transferred to SiO2. The optical properties of the regular GaN nanorods were investigated by spatially and spectrally resolved cathodoluminescence showing defect related emission only near the interface between the sapphire substrate and nanorods but not from their upper part. Micro-raman spectroscopy confirms that the single-layer graphene remains virtually unchanged in terms of the Raman signal, even after undergoing high temperatures (∼1200 °C) during nanorod growth. Furthermore, Raman mapping demonstrates that GaN structures predominantly grow on defective parts of graphene, giving new insight into the nucleation and growth mechanism of semiconductors on graphene. To validate the conductivity of graphene, when being attached to the sapphire substrate and after the nanorod growth, current-voltage investigations were carried out on single, as-grown, GaN nanorods with a nanoprober in a scanning electron microscope. These measurements demonstrate the viability of graphene as a conductive electrode, for example, as a back contact for GaN nanorods grown on insulating sapphire.

Authors with CRIS profile

Martin Heilmann Lehrstuhl für Experimentalphysik (Optik) Manuela Göbelt
Michael Latzel Lehrstuhl für Experimentalphysik (Optik)

Additional Organisation(s)

Graduiertenkolleg 1896/2 In situ Mikroskopie mit Elektronen, Röntgenstrahlen und Rastersonden Exzellenz-Cluster Engineering of Advanced Materials Interdisziplinäres Zentrum, Center for Nanoanalysis and Electron Microscopy (CENEM)

Involved external institutions

Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE) Helmholtz-Zentrum Berlin für Materialien und Energie (HZB) DE Germany (DE)

How to cite

APA:

Heilmann, M., Sarau, G., Göbelt, M., Latzel, M., Sadhujan, S., Tessarek, C., & Christiansen, S. (2015). Growth of GaN micro- and nanorods on graphene-covered sapphire: Enabling conductivity to semiconductor nanostructures on insulating substrates. Crystal Growth and Design, 15(5), 2079-2086. https://dx.doi.org/10.1021/cg5015219

MLA:

Heilmann, Martin, et al. "Growth of GaN micro- and nanorods on graphene-covered sapphire: Enabling conductivity to semiconductor nanostructures on insulating substrates." Crystal Growth and Design 15.5 (2015): 2079-2086.

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