In the growth of InGaN/GaN multi-quantum well heterostructures by metal organic chemical vapor deposition, V-defects attached to threading dislocations were observed and investigated. Energy-dispersive X-ray analysis and conventional transmission electron microscopy studies were carried out in order to determine the In composition and investigate the behavior of the dislocations. The V-defects were limited by {10▪1} lattice planes, they were attached to threading dislocations and may start at the third quantum well. The associated dislocation runs up into the overgrown GaN layer. Some (a+c) dislocations were shown to decompose inside the multi-quantum well, giving rise to a misfit segment in the c-plane and a V-shape defect.

V-Defects and Dislocations in InGaN/GaN Heterostructures. A.M.Sánchez, M.Gass, A.J.Papworth, P.J.Goodhew, P.Singh, P.Ruterana, H.K.Cho, R.J.Choi, H.J.Lee: Thin Solid Films, 2005, 479[1-2], 316-20