Characterizations of InxAlyGa1-x-yN alloy systems grown on GaN substrates by molecular-beam epitaxy
In0.05Al0.10Ga0.85N epilayers and Al0.10Ga0.90N epilayers have been grown on bulk GaN single crystals and GaN templates by radio-frequency (RF) molecular-beam epitaxy (MBE). Photoluminescence (PL) spectra at different temperatures ranged from 8 to 300 K were measured for these epilayers. The decreasing rates of PL peak intensity of the In0.05Al0.10Ga0.85N epilayers were smaller than those of the Al0.10Ga0.90N epilayers. The fluctuations of emission intensities were not observed in the In0.05Al0.10Ga0.85N epilayers by cathodoluminescence observations at 77 K. Our results indicate that In-related effects exist in InAlGaN quaternary alloys on substrates with low-dislocation densities, however, expect that the localization effect related to In-segregation is weak.
Source: Materials Science in Semiconductor Processing