ИСТИНА

The intrinsic nanoscale point defects generating in the crystal lattice of ZnSe during the crystal growth and doping processes strongly determine the functional properties of the material as well as dopants (Fe, Cr) solubility. Nonstoichiometry and IR luminescence spectra of ZnS:Cr:Fe ZnSe:Cr:Fe powdered preparations and CVD-grown ZnSe:Fe:Cr crystals treated by high-temperature gas-static pressing (HIP) were changing depending on Fe and Cr doping level and preparation conditions. Whereas the nominally pure CVD-ZnSe crystals had excess of Zn over stoichiometric composition, all the Fe-doped ZnSe crystals had an excess of chalcogen. This correlates with the results of the Zn-Se-Fe phase diagram analysis. Isothermal sections of T-x-y-z diagrams of ternary Zn-S-Fe, Zn-S-Cr and quarternary Zn-S-Fe-Cr, Zn-Se-Fe-Cr were reconstructed and experimentally confirmed by X-ray diffraction and Energy Dispersive X-ray spectroscopy (EDS) in the temperature range of 873 K - 1088 K. The homogeneity limits for ZnS:Cr:Fe and ZnSe:Cr:Fe phases have been determined. As a result of the control the intrinsic point defects Cr- and Fe-dopant levels we achieved the large quantities of differential efficiency of the produced ZnSe:Cr2 :Fe2 lasers. The research was financially supported by the Ministry of Science and High Education of the Russian Federation by the project FSSM-2020-0005