Island formation in CdSe/ZnSe superlattice (SL) structures with a moderate
defect density is investigated in a sub-monolayer range of CdSe nominal thi
cknesses. Besides the spontaneous formation of CdSe-enriched islands in def
ect-free regions, presence of dislocations crossing the SL causes an emerge
nce of the defect-attached islands. The island location near interceptions
of CdSe sheets with the dislocations produces a staircase ordering of the i
slands in neighboring SL layers. Such a mutual alignment of the CdSe-enrich
ed islands results in modified optical properties of the defect-containing
structures. Density and type of the defects promoting the laterally inhomog
eneous incorporation of Cd are controlled, in general, by the initial stage
of MBE growth and a lattice mismatch between ZnS(Be)Se cladding layers and
a GaAs substrate. (C) 2000 Elsevier Science B.V. All rights reserved.