Abstract
Aggregation processes of polymethine dyes in solutions and a heterogeneous system of AgHal microcrystals are considered. The mechanism of formation of nanoaggregates is discussed. The relationship between the aggregation and the structure of dye molecules is demonstrated. The aggregation is shown to depend on the composition and habit of AgHal microcrystals and the emulsion factors of real photographic systems. The structures and energy levels of aggregates are surveyed. The mechanism of photographic action of aggregates and ways of increasing their photochemical activity are discussed.