МАКРОСКОПІЧНА НЕОДНОРІДНІСТЬ ОПТИЧНИХ, ДІЕЛЕКТРИЧНИХ І ФОТОДІЕЛЕКТРИЧНИХ ВЛАСТИВОСТЕЙ КРИСТАЛІВ ZnSe

Abstract

The subject matter of study in the article is the optical, dielectric and photodielectric properties of ZnSe crystals containing macroscopic structural inhomogeneities. The goal of this work is to study large-scale inhomogeneities in ZnSe crystals, which is important for determining the suitability of their application in technology. The tasks to be solved are: in a crystalline ZnSe ingot of cylindrical shape in the optical range at perpendicular to the light flux orientation of the sample axis to detect macroscopic inhomogeneities and establish their relationship with the features of the dielectric properties of the local regions of the ZnSe ingot; to investigate the influence of nonmonochromatic light flux on the distribution of dielectric parameters along the axis of the ZnSe ingot containing areas of macroscopic inhomogeneities. The problems were solved by the following methods: the homogeneity of the zinc selenide ingot was studied by the polarization-optical photoelasticity method; the photometry method was used to study the intensity distribution of the light scattered by the sample perpendicular to its axis; the dielectric properties of a crystalline ZnSe ingot were investigated by the capacitive method. The following results were obtained. In ZnSe crystals regions of three types were found: isotropic, weakly anisotropic, and anisotropic. Sharp changes in the intensity of scattered light are observed in the region of large-scale optical inhomogeneity, and light scattering in this region occurs anisotropically. The angular dependences of C and tgδ at an electric field frequency of 1 kHz are obtained for the region of large-scale optical anisotropy. The changes in dielectric parameters under the action of nonmonochromatic light along the sample axis are measured. Conclusions. It was found that ZnSe crystals are characterized by large-scale inhomogeneities of the investigated properties. A close relationship is noted between the optical and electrophysical properties, which is probably due to the mutual influence of two-dimensional and point defects on the formation of a defect structure during the growth and further cooling of the crystal.