The study of elementary steps of the photolysis of silver halides by the method of microwave photoconductivity

Abstract

The major part of inconsistencies in the description of the mechanism of formation of nonhalide silver clusters under exposure to light is due to the lack of quantitative data on electronic-ionic processes in microdispersed silver halide systems. The use of the microwave photoconductivity technique partially fills the gap. The drift mobility of holes and electrons in powdered AgBr (0.8 and 60 cm2 V−1 s−1, respectively) and of electrons in powdered AgCl (40 cm2 V−1 s−1) and the rate constants of the recombination of localized electrons and free holes in powder AgBr (1.4 × 10−7 cm3 s−1) and of free electrons and holes in AgBr and AgCl (1.5 ± 0.5) × 10−11 and 2 × 10−12 cm3 s− 1, respectively) were determined. The range of the depth of traps formed by treatment with aqueous solutions of sodium thiosulfate in AgCl (0.45–0.63 eV) and by preliminary exposure of AgCl and AgBr grains (0.4 and 0.25–0.36 eV, respectively) was estimated. The rate constant of the hole capture by the centers formed by introducing AgI (7 × 10−9 cm3 s−1) was determined, and the lifetime of the Ag atom (10−4 s) was estimated. The paper summarizes the results obtained.