Absorbed Sensitizing Dyes and Ionic Conductivity of Silver Bromide Thin Films

Silver bromide thin films with (111) orientation and a thickness of about 5000 A are vacuum evaporated epitaxially onto cleaved mica in an oil-free system. The effects of cationic. anionic. and neutral dyes on the space-charge region in the AgBr film were studied by measuring the ionic conductivity and the optical absorption of the film before and after adsorption of different sensitizing dyes. The optical measurements are used to determine the configuration of the adsorbed dye. i.e., H- orJ-aggregates. The results reported in this work are compatible with previous work involving dielectric loss. It was found in the present work that the structural array of adsorbed dye molecules will affect the conductivity of the AgBr film