Abstract
Discussions were made on the relation between the mechanism of supersensitization proposed by Rosenoff et al., and that proposed by Gilman on the basis of the data of the ionization energies of sensitizing dyes in the excited triplet state I (3Dye)* estimated in this work. It was found that the values of I (3Dye*) studied by Gilman were larger and those of the dye studied by Rosenoff et al., were smaller than the electron affinity of silver halide (3.5 eV). Therefore, the dyes studied by Gilman have been thought to take part in the recombination process between a dye positive hole in the dye aggregate and an electron freed into the silver halide conduction band, and those studied by Rosenoff et al., are not. Namely, the difference of the proposed mechanisms has been thought to arise from the difference of the dyes studied. Discussions on the desensitization by sensitizing dyes have been led to the conclution that the desensitization comes from the recombination process between a photoelectron and a hole trapped by the dye aggregate, and support the above-mentioned discussions on the mechanism of supersensitization.
