Merzlikin P. Functional Solid-State Nanostructures

The thesis is devoted to determination of electronic structure of nanomaterials which have functional applications in a nanoelectronics: the nanodimensional doped and not doped films of ZnO and silicon, the nanoclusters of the silicon which have been built in a matrix of SiO2, and rotaxanes. Theoretical calculations based on the formalism of electronic density functional, a method of pseudopotential, quantum molecular dynamics of Kar-Parinello which belong to the class of ab-initio methods are chosen as the main method of research. The most probable stabilization mechanisms of polar surfaces of thin ZnO films in thickness of 4–7 A, namely stabilization at the expense of non-uniform compression of layers or at the expense of hydrogen adsorption were determined. It was established that the doping of a thin ZnO film in thickness of 7 A by atoms of copper and silver in concentration of 4 % or 12,5 % leads to formation of new energy levels in the range of occupied states whereas the doping by carbon in concentration of 4 % doesn’t cause emergence of additional states. It is shown that the system of nanofilms of ZnO which are located at distance ~5 A one from another, acts as the electric relay which becomes closed by electronic crossing point in a vacuum interval between films at adsorption of polar molecules of gas. It was predicted the receiving of periodically repeating areas with the increased value of electronic density in a silicon film in thickness of 5 A at periodic adsorbing on a film surface of flat organic molecules with non-uniform distribution of electronic density. It was theoretically determined that the nanocrystal of silicon built in SiO2 leads to emergence of low-populated states in the valence band and band gap at the expense of emergence of positive Si ions in SiO2 matrix. The potential relief of two-positional rotaxane transition between stable states was defined.