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The yellow luminescence (YL) band with a maximum at 2.2 eV is the dominant defect‐related luminescence in unintentionally doped GaN. The discovery of the mechanism responsible for this luminescence band and related defects in GaN took many years. Eventually, a consensus has been reached that the CNacceptor is the source of the YL band (the YL1 band) in GaN samples grown by several techniques. Previously suggested candidates, such as VGa, VGaON, CNON, and CNSiGa, should be discarded. At the same time, other defects (such as the VN, BeGa, and CaGa) may cause luminescence bands with positions and shapes not much different from the YL1 band. In GaN containing high concentrations of gallium vacancies, oxygen, and hydrogen, complexes containing these species may also contribute in the red–yellow part of the photoluminescence spectrum. The main controversies related to the YL band are resolved.
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Photoluminescence from Vacancy‐Containing Defects in GaN
Photoluminescence (PL) bands in GaN associated with point defects involving nitrogen or gallium vacancy (VNor VGa) are reviewed. The VN‐containing defects, including the isolated VNand its complexes with acceptors, are often observed in PL from semi‐insulating GaN and are responsible for the green (GL2) and red (the RL2 family) bands. The complexes of the VGawith hydrogen and oxygen are abundantly formed in n‐type GaN grown by the ammonothermal method. Some of these complexes are responsible for PL bands in the red‐yellow region of the PL spectrum.
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- Award ID(s):
- 1904861
- PAR ID:
- 10415372
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- physica status solidi (a)
- Volume:
- 220
- Issue:
- 10
- ISSN:
- 1862-6300
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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