Khmelenko O. The influence of dislocations on the structure and properties of sulfide and zinc selenide crystals

Object of research - the interactions of growth dislocations with other defects, as well as their influence on optical, electrical and structural properties of crystals of sodium sulfide and zinc selenide. Objective - to establish the nature of the features of optical and electrical properties observed in the initial stages of plastic deformation in crystals of sodium sulfide and zinc selenide. Methods of research - electron paramagnetic resonance measurements and analysis of the photoluminescence spectra, spectra of thermally stimulated depolarization and electrical conductivity of semiconductors. A comprehensive study of the influence of plastic deformation on the luminescence properties of zinc sulfide crystals has allowed to determine the amount of manganese emission centers that are in the zone of influence of electric fields motionless dislocations. From the temperature positions of the maxima of the TSD current peaks were evaluated activation energy of electrically active defects, and demonstrates that plastic deformation leads to the destruction of defects at a depth of 0.2 eV and the appearance of the donor centers of energy deposition 0.018 eV. Based on the analysis of EPR spectra and electrical conductivity properties of crystals, stimulated by the deformation, the proposed model that adequately explains the physics of the processes leading electronic system of deformed crystals to exit out of balance. It is shown that the relaxation of conductivity to the initial value is thermally reversible with an activation energy of about 0.8-1.0 eV. An analysis of the excitation spectra and the deformation of crystal structure transformations of ZnS and ZnSe, it is concluded that in ZnSe crystals for Mn2 + ions begin to act strong electric fields of dislocations. This effect creates an imbalance and leads to a decrease in the concentration of Mn2 + and an increase in electrical conductivity.