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Vertical GaN nanocolumns grown on graphene intermediated with a thin AlN buffer layer

Abstract

We report on the self-assembled growth of high-density and vertically-oriented n-doped GaN nanocolumns on graphene by radio-frequency plasma-assisted molecular beam epitaxy. Graphene was transferred to silica glass, which was used as the substrate carrier. Using a migration enhanced epitaxy grown AlN buffer layer for the nucleation is found to enable a high density of vertical GaN nanocolumns with c-axis growth orientation on graphene. Furthermore, micro-Raman spectroscopy indicates that the AlN buffer reduces damage on the graphene caused by impinging active N species generated by the radio-frequency plasma source during the initial growth stage and nucleation of GaN. In addition, the grown GaN nanocolumns on graphene are found to be virtually stress-free. Micro-photoluminescence measurements show near band-edge emission from wurtzite GaN, exhibiting higher GaN bandgap related photoluminescence intensity relative to a reference GaN bulk substrate and the absence of both yellow luminescence
and excitonic defect emission. Transmission electron microscopy reveals the interface of GaN nanocolumns on graphene via a thin AlN buffer layer. Even though the first few monolayers of AlN on top of graphene are strained due to in-plane lattice mismatch between AlN and graphene, the grown GaN nanocolumns have a wurtzite crystal structure without observable defects. The results of this initial work pave the way towards realizing low-cost and high-performance electronic and optoelectronic devices based on III-N semiconductors grown on graphene.
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Category

Academic article

Language

English

Author(s)

  • Andreas Liudi Mulyo
  • Mohana Rajpalke
  • Haruhiko Kuroe
  • Per Erik Vullum
  • Helge Weman
  • Bjørn-Ove Fimland
  • Katsumi Kishino

Affiliation

  • SINTEF Industry / Materials and Nanotechnology
  • Norwegian University of Science and Technology
  • Sophia University Tokyo

Year

2018

Published in

Nanotechnology

ISSN

0957-4484

Volume

30:049601

Issue

1

Page(s)

1 - 9

View this publication at Norwegian Research Information Repository