Study on electron and energy transfer in highly organezed aggregates by quantum beams

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Langmuir Blodgett films of cyanin dye and arachiadic acid on the substrates or quarts were found to decompose very little by irradiation of UV and visible light, but to decompose markedly with gama radiation and electron beams in the atmosphere of Ar to yield very large G values. This large G value was considered to arize from the energy transfer from the substrate to the LB layrs, but was finally attributed to the attack of the radiolysis species of Ar in the gas phase. Gamma radiolysis and pulse radiolysis experiments of the cyanin dye solutions revealed that the major contribution to the decomposition of the dye comes from the Ar^+ ion species.Observation of the LB membranes with fluorescence microscope showed that the decomposition of the J aggregates of the dyes induced by radiation is largely affected by the domain structures of the J aggregates in the dye membranes, and the highly developped domains of the J agregates was found from the observation of the LB films to have highly … More ordered structure of the dye molecules and it was inferred that electron and energy transfers between the highly ordered and the less ordered molecules or the monomers of the dyes are deeply related to the decomposition reactions of the dyes.On the other hand, the LB membranes of the arachiadic acid on the substrates of silicon were prepared and their XPS spectra showed that the strong chemical interactions exist between the arachiadic acid molecules and the silicon atoms on the surface of the substrates. Based on this experimental results, the thin membranes of dioctadecyl-dithiocarbamate (DOTC) on the substrate of GaAs were prepared using electrochemical deposition method to cheek the possibility of stabilizing the dangling bonds of the GaAs surfaces with the sulfur atoms in the DOTC layrs that become stable and thin isulator. The XPS spectra of the membranes showed that chemical bonds are formed between the sufur atoms in DOTC and the As atoms in the surface of GaAs, and the density of the surface states of the samples was found from their photoluminescence spectra to be reduced markedly with this treatment. Less