The influence of dislocation density on photoluminescence intensity was investigated experimentally and compared to a model. Samples were grown by molecular beam epitaxy and metal-organic chemical vapour deposition. Different growth parameters and thicknesses of the layers resulted in differing dislocation densities. The threading dislocation density, measured by atomic force microscopy, scanning electron microscopy and X-ray diffraction, ranged from 5 x 108 to 3 x 1010/cm2. A model which accounted for the photoluminescence intensity as a function of dislocation density was developed. The model showed good agreement with experimental results for typical GaN dislocation densities, 5 x 108 to 1010/cm2.

Influence of Dislocation Density on Photoluminescence Intensity of GaN. J.F.Fälth, M.N.Gurusinghe, X.Y.Liu, T.G.Andersson, I.G.Ivanov, B.Monemar, H.H.Yao, S.C.Wang: Journal of Crystal Growth, 2005, 278[1-4], 406-10