Chugaj O. Physical basis of modification of AIIBVI crystal properties by forming the naturally ordered defect structure.

The object: wide band-gap AIIBVI crystals grown under various conditions and exposed to extreme external effects. The aim: development of physical basis of modification of AIIBVI crystal properties by forming the naturally ordered defect structure. Investigation methods: optical microscopy, photoelasticity, X-ray structure analysis, scanning electron microscopy, method of "resonance-antiresonance", linear thermal expansion, dielectric and photodielectric spectroscopy. It was found that growth in essentially non-equilibrium conditions forms the ordered assemblage of structure defects causing respective internal fields. This leads to essential changes in acoustic, thermal, dielectric, and photoelectric crystals properties. The properties also become modified due to forming the ordered defect structure and to evolution of internal fields under extreme external actions. An original method of scanning photodielectric spectroscopy was proposed, which provides measuring of the energy position and sub-surfaceelectrostatic potential in semiconductors. These peculiarities were connected with ordered arrays of two-dimensional structure defects, Te dopant atoms, influence of uniaxial compression and stationary electric field. Irreversible changes in the energy spectrum and sub-surface electrostatic potential connected with the influence of small dozes of ionizing radiation were revealed. Field of application: physics of solid state.