Energy spectra and electronic structure of twodiensional covalent cristals with local defects

The models of a cluster with hydrogen boundary atoms and periodical cluster and density functional theory (DFT) in valent base STO-3G (with the account of a pseudopotential of core electrons) are applied for study of the peculiarities of electronic structure and energy spectra of twodimensional covalent structures (on the basis of diamond, silicon, germanium) with the chosen surface covered with atoms of hydrogen (in 111 -direction). The effects coursed by surface defects of substitution Element-Н on atoms B, Al, Ga and atoms Н on atoms F and Cl are discussed.