Low-energy cathodoluminescence spectroscopy of erbium-doped gallium nitride surfaces

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Journal of Vacuum Science and Technology, A

DOI:https://doi.org/10.1116/1.582079· OSTI ID:698839

Levin, T M; Young, A P ^[1]; Schaefer, J ^[2]; Brillson, L J ^[3]; MacKenzie, J D; Abernathy, C R ^[4]

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1. Department of Electrical Engineering, The Ohio State University, Columbus, Ohio 43210 (United States)
2. Center for Materials Research, The Ohio State University, Columbus, Ohio 43210 (United States)
3. Department of Electrical Engineering and Center for Materials Research, The Ohio State University, Columbus, Ohio 43210 (United States)
4. Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)

We have used cathodoluminescence spectroscopy with variable incident beam energies to study the energy levels and activation of Er impurities in GaN as a function of depth below the free surface. The GaN films were doped {ital in situ} during either metalorganic molecular-beam epitaxy (MOMBE) or molecular-beam epitaxy (MBE). Besides the well-known Er{sup 3+} luminescence at 0.80 eV, we observe emissions at 1.2, 1.8, 2.2, and 2.3 eV, corresponding to higher energy Er 4{ital f} shell transitions. For unannealed MOMBE-grown GaN:Er, these higher energy emissions appear only for excitation depths of hundreds of nanometers. The MOMBE-grown GaN;Er annealed to 500&hthinsp;{degree}C shows a dramatic increase in the 1.8, 2.2, and 2.3 eV peak intensities at shallow probe depths, with its yield increasing with increasing depth. These three features become pronounced at all depths after a 700&hthinsp;{degree}C anneal. MBE-grown GaN:Er grown with lower C and O impurity levels than the MOMBE-grown sample exhibits strong emission at all these energies without annealing. The decreased emission at shallow (tens of nanometer) probe depths suggests a depletion of activation Er in the near-surface region. Enhancement of near-surface Er{sup 3+} luminescence with annealing may be due to lattice reordering as well as impurity redistribution. {copyright} {ital 1999 American Vacuum Society.}

• OSTI ID: 698839
• Journal Information: Journal of Vacuum Science and Technology, A, Journal Name: Journal of Vacuum Science and Technology, A Journal Issue: 6 Vol. 17; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANNEALING
CATHODOLUMINESCENCE
DOPED MATERIALS
ERBIUM
ERBIUM ADDITIONS
GALLIUM COMPOUNDS
GALLIUM NITRIDES
IMPURITIES
MOLECULAR BEAM EPITAXY