Pavlov V. Optical and electrophysical properties of zinc selenide single crystals doped by transition metals elements.

The thesis is devoted to clearing up of influencing of chrome and cobalt impurities on the absorption spectra in visible and infra-red spectral range of zinc selenide crystals, determination of nature of optical transitions, and also determination of diffusion coefficients of these activators in ZnSe single crystals.Researches of optical absorption spectra of ZnSe:Cr crystals estab-lished the presence of characteristic bands in the blue-green region. In area of absorption edge of the ZnSe:Co crystals found out the se-ries of weak absorption lines on 2.36, 2.43, 2.47 and 2.55 eV. These lines are the result of intra-shell electronic transitions. The shift of absorption lines of the ZnS:Co, ZnSe:Co, ZnTe:Co crystals is stipu-lated by the increase of ionic radius of anions in the sequence S - Se - Te. The diffusion coefficients of the investigated impurities in the ZnSe crystals in a temperature range 1073-1273 K are calculated. Doping of ZnSe by chrome and cobalt impurities leads to formation of deep donor centers with activation energy 0.65 eV, which the atoms of in-terstice zinc Zni are. The presence of photoconductivity at the ZnSe:Cr and ZnSe:Co crystals at illumination by their light from the visible region of spec-trum is shown.