On the impact of indium distribution on the electronic properties in InGaN nanodisks

Journal Article · Mon Mar 09 00:00:00 EDT 2015 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4915117· OSTI ID:22395704

Sigle, W.; Aken, P. A. van ^[1]; Ng, T. K.; Ooi, B. S. ^[2]; El Bouayadi, R. ^[3]; Jahangir, S.; Bhattacharya, P. ^[4]

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1. Max Planck Institute for Intelligent Systems, Heisenbergstraße 3, 70569 Stuttgart (Germany)
2. Photonics Laboratory, King Abdullah University of Science and Technology, Thuwal 23955-6900 (Saudi Arabia)
3. LPMR, Université Mohammed Premier, B.P. 717, 60000 Oujda (Morocco)
4. Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2122 (United States)

We analyze an epitaxially grown heterostructure composed of InGaN nanodisks inserted in GaN nanowires in order to relate indium concentration to the electronic properties. This study was achieved with spatially resolved low-loss electron energy-loss spectroscopy using monochromated electrons to probe optical excitations—plasmons—at nanometer scale. Our findings show that each nanowire has its own indium fluctuation and therefore its own average composition. Due to this indium distribution, a scatter is obtained in plasmon energies, and therefore in the optical dielectric function, of the nanowire ensemble. We suppose that these inhomogeneous electronic properties significantly alter band-to-band transitions and consequently induce emission broadening. In addition, the observation of tailing indium composition into the GaN barrier suggests a graded well-barrier interface leading to further inhomogeneous broadening of the electro-optical properties. An improvement in the indium incorporation during growth is therefore needed to narrow the emission linewidth of the presently studied heterostructures.

• OSTI ID: 22395704
• Journal Information: Applied Physics Letters, Vol. 106, Issue 10; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
77 NANOSCIENCE AND NANOTECHNOLOGY
CONCENTRATION RATIO
DIELECTRIC MATERIALS
ELECTRONIC STRUCTURE
ELECTRONS
EMISSION
ENERGY-LOSS SPECTROSCOPY
EPITAXY
FLUCTUATIONS
GALLIUM NITRIDES
INDIUM COMPOUNDS
INTERFACES
NANOWIRES
OPTICAL PROPERTIES
PLASMONS