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We have studied the photoluminescence spectra, including the time-resolved ones, and the photodiffusion spectra of PbI2 crystals and Pb1-xCdxI2 solid solutions. It is established that these crystals have monopolar (hole) photoconductivity. The possibility of the formation of PbI2 clusters with various sizes in solid solutions is shown. It is found that the value of splitting between Γ3–- and Γ1–-exciton states in such clusters is 30 and 36 meV for x = 0.50 and x = 0.70, respectively. We have revealed that, for x = 0.50, the self-trapping excitons in PbI2 clusters happens., Проведено дослідження спектрів фотолюмінесценції, в тому числі із розділенням в часі, і фотодифузійного струму кристалів PbI2 та твердих розчинів Pb1-xCdxI2. Встановлено, що дані кристали мають монополярну (діркову) провідність. Показанаможливість утворення в твердих розчинах кластерів PbI2 різних розмірів. Встановлено, що величина розщеплення між Γ3–- та Γ1–-екситонними станами в таких кластерах становить 30 та 36 меВ для x = 0,50 та x = 0,70, відповідно. Виявлено, що для x ≥ 0,50 має місце автолокалізація екситонів в кластерах PbI2.

Annealing in air and vacuum were obtained glass samples Li2B4O7:Ag,Gd with Ag NPs. Three methods: the half-width strip plasmon resonance, X-ray diffraction and Small-angle X-ray scattering, in these samples by size NPs Ag. Revealed that the size of NPs Ag, defined by half-widths plasmon resonance band much smaller than obtained by other methods. It is concluded that the methods of X-ray diffraction and small-angle X-ray scattering give results closer to reality than the method plasmon resonance.

Investigations of alkaline Li₂B₄O₇:Ag and alkaline-earth CaB₄O₇:Ag tetraborate glasses with Ag nanoparticles (Ag NPs) formed by thermal treatment in vacuum have been performed. It is ascertained that in volumes of the both glasses a small number of Ag NPs is formed, whereas their main mass is concentrated near the samples surface. It is obtained from the plasmon resonance results that, under the same annealing conditions, concentration of the Ag NPs in the near-surface layer of CaB₄O₇:Ag glass is appreciably smaller than in the near-surface layer of Li₂B₄O₇:Ag glass. This peculiarity is explained by difference between contributions of alkaline Li⁺ and alkaline-earth Ca²⁺ ions to processes of the Ag NPs formation in respective tetraborate glass. Remove selected

The electron trapping and detrapping processes in the semi-insulating CdTe:V crystals have been studied using a new time-resolved photoelectric spectroscopy technique. It has been shown that the electron processes in such crystals involving the impurity centers and intrinsic defects are fast and occur in the nanosecond range. The information on the nature and energy structure of the anisotropic impurity centers has been obtained. Two different photogeneration mechanisms of free electrons have been revealed: the direct photoionization of electrons from the ground impurity states and their self-ionization from the excited impurity states which are in resonance with the conduction band. It was found that the photosensitivity region for Cd₁₋ₓHgₓTe:V crystals (x = 0.018) at 300 K is in the range from 0.9 to 1.7 μm.