| Since silver halides are sensitive only to the blue part of the visible spectrum, it is necessary to extend this sensitivity in the rest of the visible spectrum by adsorbing dyes at the surface of the microcrystals. The adsorbed dye molecules or aggregates can act as deep traps for holes.;A new way of acquiring kinetic information about the formation and decay of dye radicals is introduced using the electron spin resonance technique. Two quantitative models are introduced to describe the formation and decay kinetics of the dye radicals during and after irradiation. These models are able to fit the experimental data very well. It is possible to estimate the efficiency of hole trapping by the dye, the stability of the trapped hole and the efficiency of electron injection in the process of spectral sensitization.;Several results have given us new insights in the photographic process.;In this work the kinetics of hole trapping and the stability of the trapped holes on the dye molecules or aggregates is studied. Because hole trapping leads to the formation of dye radicals, the electron spin resonance (ESR) technique can be used to obtain kinetic information. |
