Various techniques of transmission electron microscopy were used to study the Cd distribution and the formation of defects in CdSe/ZnSe structures with a nominal CdSe layer thickness of 3 monolayers, and ZnSe cap-layer thicknesses which ranged from 20 to 60nm. The samples were grown by means of standard molecular-beam epitaxy at 350C. The configurations of defects which arose, in CdSe/ZnSe structures, from a critical thickness greater than 2.5 monolayers was studied. The defects originated in Cd-rich regions close to the CdZnSe layer, and consisted of stacking-fault pairs on {111} crystal planes. The lengths of the dislocation lines and the sizes of the stacking-faults increased with the cap-layer thickness. Quantitative measurements of the Cd distribution indicated segregation with an efficiency of 0.74.

Transmission Electron Microscopy Investigation of CdSe/ZnSe Quantum Dot Structures. D.Litvinov, A.Rosenauer, D.Gerthsen, H.Preis: Physica Status Solidi B, 2002, 229[1], 523-7