Abstract
In high-purity GaN grown by hydride vapor phase epitaxy, the commonly observed yellow luminescence (YL) band gives way to a green luminescence (GL) band at high excitation intensity. We propose that the GL band with a maximum at 2.4 eV is caused by transitions of electrons from the conduction band to the 0/+ level of the isolated ${\mathrm{C}}_{\mathrm{N}}$ defect. The YL band, related to transitions via the \ensuremath{-}/0 level of the same defect, has a maximum at 2.1 eV and can be observed only for some high-purity samples. However, in less pure GaN samples, where no GL band is observed, another YL band with a maximum at 2.2 eV dominates the photoluminescence spectrum. The latter is attributed to the ${\mathrm{C}}_{\mathrm{N}}{\mathrm{O}}_{\mathrm{N}}$ complex.
Highlights
Gallium nitride (GaN) is a promising material for high-power/high-frequency electronics [1,2,3,4]
The yellow luminescence (YL) band in GaN grown by metal-organic chemical vapor deposition (MOCVD) has a maximum at 2.2 eV (Figs. 2 and 3)
In conductive n-type GaN, the YL band intensity begins to saturate at excitation intensities Pexc > 10−5 W/cm2 (Fig. 2)
Summary
Gallium nitride (GaN) is a promising material for high-power/high-frequency electronics [1,2,3,4]. The YL and GL bands were attributed to transitions of electrons from the conduction band to the 2−/− and −/0 transition levels, respectively, of the gallium vacancy-oxygen (VGaON) complex [6]. The exponential decay of the GL band at low temperatures was explained with the assumption that the GL band is caused by transitions of electrons from an excited state, located very close to the conduction band minimum (CBM), to the −/0 level of the VGaON acceptor [5]. Such an assumption is not well justified. A revision of the attribution for the GL band in GaN is needed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
