Deep hole traps in undoped n-GaN films grown by hydride vapor phase epitaxy

In-Hwan Lee, A. Y. Polyakov, N. B. Smirnov, A. V. Govorkov, A. S. Usikov, H. Helava, Yu N. Makarov, S. J. Pearton

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28 Citations (Scopus)

Abstract

Deep hole traps were studied in bulk free-standing GaN crystals and in thinner (10-20μm) GaN films prepared by hydride vapor phase epitaxy (HVPE) on sapphire. Six hole traps in different combinations were detected in these crystals, H1 (activation energy 0.92-0.94eV), H2 (0.55eV), H3 (0.65-0.7eV), H4 (0.85-0.9eV), H5 (1.1-1.2eV), and H6 (0.95-1.05eV). The dominant traps in all samples were the H5 and H6 traps that were attributed, respectively, to gallium vacancy complexes with oxygen (VGa-O) and substitutional carbon related centers. We associate the H5 hole traps with the red luminescence bands, the H4 hole traps with the green luminescence bands, and the H6 hole traps with the yellow luminescence bands often observed in HVPE GaN. These attributions are based on the low energy thresholds of the deep traps optical excitation spectra and the depth of the respective trap levels.

Original languageEnglish
Article number223702
JournalJournal of Applied Physics
Volume115
Issue number22
DOIs
Publication statusPublished - 2014 Jun 14
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)

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    Lee, I-H., Polyakov, A. Y., Smirnov, N. B., Govorkov, A. V., Usikov, A. S., Helava, H., Makarov, Y. N., & Pearton, S. J. (2014). Deep hole traps in undoped n-GaN films grown by hydride vapor phase epitaxy. Journal of Applied Physics, 115(22), [223702]. https://doi.org/10.1063/1.4882715