Tight-binding calculations of SiGe alloy nanocrystals in SiO matrix.

In the empirical tight-binding approach we study the electronic states in spherical SiGe nanocrystals embedded in SiO matrix. For the SiGe alloy and the matrix we use the virtual crystal approximation. The energy and valley structure of electron states is obtained as a function of Ge composition and nanocrystal size.