Fachgruppe Nanostrukturierte Materialien    

The structural properties of two epitaxial model systems were investigated, NiMnSb thin films on a (In,Ga)As/InP(001) substrate and free-standing CdSe quantum dots on a ZnSe(001) surface. For the first system the influence of surface-oxidation on the relaxation behavior of the entire film was investigated by a comparison of capped and uncapped samples. We found that the critical thickness for pseudomorphic growth is more than doubled by the protective capping layers. For the second system under investigation a determination of the size and shape of the quantum dots was performed. They have a cylindrical shape with an almost constant diameter of ?10 nm and a height of about 2 nm, whereby the lowermost region widens up to about 14 nm. The entire quantum dots are strained.