An overall characterization of the GaN and AlGaN/GaN epitaxial layers was carried out by means of X-ray diffractometry and optical spectral analysis. The layers were grown, by using metal-organic gas-phase epitaxy, onto (00▪1)-oriented single-crystal sapphire wafers. The components of strains and the density of dislocations were determined. The effects of strain and dislocations upon the photoluminescence intensity and spectra were studied. The results permitted a better understanding to be obtained as regards the nature and mechanisms of the formation of defects in the epitaxial AlGaN/GaN heterostructures.

Interface Structural Defects and Photoluminescence Properties of Epitaxial GaN and AlGaN/GaN Layers Grown on Sapphire. V.P.Kladko, S.V.Chornenkii, A.V.Naumov, A.V.Komarov, M.Tacano, Y.N.Sveshnikov, S.A.Vitusevich, A.E.Belyaev: Semiconductors, 2006, 40[9], 1060-5