Investigation of the “self-desensitization” processes in anionic dye by means of the luminescence method

Abstract

The luminescence-based technique is proposed that permits to control the interaction processes of molecular and polymolecular forms of the anionic dye AgHal emulsions, responsible for the self-desensitization. It is found that the characteristic feature of the I-kind self-desensitization is the molecular dye phosphorescence occurring upon the immediate transfer of the non-equilibrium electrons and holes from the excited J-aggregate to the molecular dye. The characteristic feature of the II-kind self-desensitization is the anomalously retarded anti-Stokes fluorescence of the molecular dye associated with the transfer of the non-equilibrium electrons from the excited J-aggregate to silver in the atomic-molecular degree of dispersion, part of which can afterwards be transferred to the molecular dye and recombine there with the localized non-equilibrium holes. Additional infra-red illumination enabled us to show experimentally that the anomalously retarded anti-Stokes luminescence of the molecular dye and the phosphorescence of the molecular dye upon excitation of the dye J-aggregates, take place in different dye molecules and are determined by different electron-hole processes and different interactions of the
molecules with the dye J-aggregates.