Comments on a peak of AlxGa1-xN observed by infrared reflectance

Abstract Al x Ga 1 − x N epilayers, grown on c -plane oriented sapphire substrates by metal organic chemical vapour deposition (MOCVD), were evaluated using FTIR infrared reflectance spectroscopy. A peak at ∼850 cm −1 in the reflectance spectra, not reported before, was observed. Possible origins for this peak are considered and discussed.