A direct correlation between the structural and luminescence properties of thick InxGa1-xN layers was achieved on a microscopic scale by using highly spatially resolved cathodoluminescence. Surface roughening was typically observed in growth by metal-organic vapor phase epitaxy of thick InxGa1-xN layers for x-values greater than 0.1. Although the film remains highly planar, craters and protrusions appeared on the surface. These surface defects were associated with red-shifted luminescence indicative of In segregation, and were related to threading dislocations in the films.

Microscopic Correlation of Red-Shifted Luminescence and Surface Defects in Thick InxGa1–xN Layers. F.Bertram, S.Srinivasan, L.Geng, F.A.Ponce, T.Riemann, J.Christen: Applied Physics Letters, 2002, 80[19], 3524-6