Molecular beam epitaxy of silicon±germanium nanostructures

The current status of the research in the ®eld of synthesis and application of silicon and germanium-based nanostructures formed by the process of 3D island self-organization is reviewed in the present paper. There was an obvious conclusion that elastic deformations in epitaxial ®lms and 3D islands are the key factor which is not only the reason of the transition from planar to Stranski±Krastanow mechanism of growth, but also in¯uences the next stages of islands evolution including their shape, size and spatial distributions. There are many cases when this factor makes crucial changes to the classical set of phase-formation mechanisms right up to an equilibrium coexistence of islands on a surface. Various types of ordering were classi®ed in the nanocluster systems under consideration: in cluster shape, in its size, in the distance between nearest islands, as well as ordering through vertical, i.e. in successively growing multilayer structures containing quantum dots. The results of recent original investigations of electrical and optical properties of self-assembled arrays of Ge quantum dots ar