Effect of stacking faults on the photoluminescence spectrum of zincblende GaN
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Authors
Church, SA
Hammersley, S
Mitchell, PW
Kappers, Menno
Frentrup, Martin
Shaw, LJ
Oliver, Rachel
Binks, DJ
Dawson, P
Publication Date
2018-05-14Journal Title
Journal of Applied Physics
ISSN
0021-8979
Publisher
AIP Publishing
Volume
123
Number
185705
Type
Article
Metadata
Show full item recordCitation
Church, S., Hammersley, S., Mitchell, P., Kappers, M., Lee, L. Y., Massabuau, F., Sahonta, L., et al. (2018). Effect of stacking faults on the photoluminescence spectrum of zincblende GaN. Journal of Applied Physics, 123 (185705)https://doi.org/10.1063/1.5026267
Abstract
The photoluminescence spectra of a zincblende GaN epilayer grown via metal-organic chemical vapour deposition upon 3C-SiC/Si (001) substrates were investigated. Of particular interest was a broad emission band centered at 3.4 eV, with a FWHM of 200 meV, which extends above the bandgap of both zincblende and wurtzite GaN. Photoluminescence excitation measurements show that this band is associated with an absorption edge centered at 3.6 eV. Photoluminescence time decays for the band are monoexponential, with lifetimes that reduce from 0.67 ns to 0.15 ns as the recombination energy increases. TEM measurements show no evidence of wurtzite GaN inclusions which are typically used to explain emission in this energy range. However, dense stacking fault bunches are present in the epilayers. A model for the band alignment at the stacking faults was developed to explain this emission band, showing how both electrons and holes can be confined adjacent to stacking faults. Different stacking fault separations can change the carrier confinement energies sufficiently to explain the width of the emission band, and change the carrier wavefunction overlap to account for the variation in decay time.
Relationships
Is supplemented by: https://doi.org/10.15127/1.304093
Sponsorship
This was work funded by EPSRC under Grant Nos. EP/M010627/1 and EP/N01202X/1, and Innovate UK under Grant No. 56917-383420.
Funder references
EPSRC (EP/M010589/1)
EPSRC (EP/N01202X/1)
EPSRC (EP/R01146X/1)
Identifiers
External DOI: https://doi.org/10.1063/1.5026267
This record's URL: https://www.repository.cam.ac.uk/handle/1810/279729
Rights
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