Direct evidence was found for In segregation in InGaN/GaN quantum-well structures by carrying out highly spatially resolved energy dispersive X-ray analyses in a dedicated scanning transmission electron microscope. The In fluctuations became increasingly marked in the vicinity of the dislocations. The latter assisted In diffusion, and caused severe Ga/In intermixing.

Indium Segregation in InGaN Quantum-Well Structures N.Duxbury, U.Bangert, P.Dawson, E.J.Thrush, W.Van der Stricht, K.Jacobs, I.Moerman: Applied Physics Letters, 2000, 76[12], 1600-2