[en] With using the quantum-chemical tight binding method the stabilities of hollow silicon clusters are investigated in the process of quasi-one-dimensional growth. The obtained hexagonal structures of clusters Si₂₄ and Si₂₆ can be the 'building units' of a silicon nanowire. (authors)

[en] Effect of the surface passivation by hydrogen atoms of the diamond-like nanoclusters Si_2_9 and Si_3_8, and also surface-reconstructed clusters Si__2_9D and Si_3_8D on structure, charge distribution and energetic gap between high occupied and low unoccupied molecular orbitals has been studied by combination of the non-conventional tight-binding method and molecular dynamic. It is shown that cluster surface passivation leads to widening of silicon kern, redistribution of charges on atoms and changing the energy gaps. The width of the HOMO-LUMO gap of surface-reconstructed clusters Si_2_9D and Si_3_8D increases from 0.02 eV upto ∼ 1 eV, when the number of hydrogen atoms on surface rise. HOMO-LUMO gap of diamond-like nanoclusters has broadened upto 2.8 eV for fully saturated cluster. (authors)

[en] In the paper a model of formation of structural defect states in semiconductors caused by the radiation-stimulated recombination of vacancies with impurity atoms has been suggested. An analytical expression for determination of the concentrations of impurities, vacancies and complexes formed at the interactions of vacancies and impurities has been finally obtained. A new model has been suggested, taking into account the back reactions of vacancies with interstitial atoms and additional interactions between interstitial atoms and impurity atoms. For the set of kinetic equations of the model an exact analytic solution has been obtained for the case of equality of recombination rates for the vacancies with impurities and interstitial atoms, at the neglecting of the recombination rates between interstitial and impurity atoms. Numerical calculations of complex's formation have been obtained. (authors)