The effect of an In surfactant, during metalorganic vapour phase epitaxial growth on sapphire substrates, was studied by using time-resolved photoluminescence, cathodoluminescence and scanning electron microscopy. The samples were divided into 2 groups, in which H or N were used as a carrier gas during growth. It was shown that In-doped samples had a lower dislocation density, a narrower photoluminescence linewidth and a longer free exciton lifetime. The effect of In was greater for layers which had been grown under N-rich conditions. The improvements in structural and optical properties were attributed to the effect of the In upon dislocations.

Optical Spectroscopy of GaN Grown by Metalorganic Vapor Phase Epitaxy using Indium Surfactant G.Pozina, J.P.Bergman, B.Monemar, S.Yamaguchi, H.Amano, I.Akasaki: Applied Physics Letters, 2000, 76[23], 3388-40