Photographic effects of electron and positive hole traps in silver halides- 4

In the present investigation, studies have been made on the mechanism of reduction sensitization in small silver bromide grains (about 0. 27 U) and in cubic silver bromide grains (about 0. 7 U) in order to see the effect of the nature of silver bromide grains on the mechanism of reduction sensitization. It is suggested from these results that the mechanism of reduction sensitization depends upon the nature of unsensitized grains. The sensitivity centers of reduction sensitization in this view are positively charged silverpecks which act as electron traps in the cases of tabular and large octahedral grains, and electrically neutral silver specks which act as positive hole traps in the cases of cubic and small grains. Moreover, it has been suggested that the behavior of the formation of silver specks during reduction sensitization also depends upon the grains.