Zhukov S. “The Pfoto-induced physico-chemical processes and their sensitization in microsystems a «core – silver-halide shell”

By using the methods of general and spectral sensitometry, low-temperature time-resolving luminescent spectroscopy, electronic microscopy and absorbtion spectroscopy, we study the composition of photosensitivity centers and the associated mechanisms of luminescence of AgBr(I) emulsion microcrystals (EMC) distributed in various binders. The mechanisms of luminescence of EMC AgBr(I) in photo-excitation of the silver halide (case of the Stokes luminescence) and photo-excitation of the dye adsorbed on the EMC AgBr(I) surface in various aggregate states (case of the anti-Stokes luminescence) are considered. The mechanisms of self-desensitization of dyes of types I and II are indicated, due to the interaction of the molecular and aggregated dye. The possibility of chemical sensitization after the spectral one from the gas phase has been established. Luminescent and absorption methods have established the interaction of nanoclusters (Ag2S)n and (Ag2O)m located on the surface of EMC AgHal with dyes in various aggregate states. A new type of spectral sensitization of heterophase microsystems (HMS) “CaF2 core –AgBr shell” is considered, where the dye is located on the inner surface of the photosensitive shell and causes the expansion of the spectral range of sensitization towards the longwave spectral range due to the removal of the dye self-desensitization effect. Spectral sensitization of the internal and external surfaces of the photosensitive shell with different dyes was performed. Compared with the spectrosensity and luminescent data of the HMS “CaF2 – AgBr core – shell” and microsystems (MS) “AgBr(I) – AgBr core – shell”, it was established that the planting of anionic dye with a photosensitive shell appears due to the bivalent cationic component of the core. In the case of MS “AgBr(I) core – AgBr – shell”, cationic components of the cores and shells do not differ, and therefore the dye is squeezed out to the outer surface of the shell.