An investigation was made of the structural characteristics of non-luminescent areas, in degraded II-VI blue light emitters, by using electroluminescence and transmission electron microscopy. Dark triangular non-luminescent defects, which were observed in the separate confinement heterostructure laser structures, were spread out in the <100> direction and consisted of a high density of dislocation dipoles and loops. The sources of these defects were pre-existing stacking faults which originated at the II-VI epilayer/GaAs interface. The dipoles themselves were aligned along both of the <110> directions and lay in the {111} plane. Their Burgers vectors were of a/2<011> type and were inclined at 45 to the (001) junction plane.

S.Tomiya, M.Ukita, H.Okuyama, K.Nakano, S.Itoh, A.Ishibashi, E.Morita, M.Ikeda: Materials Science Forum, 1995, 196-201, 1109-16