Pulsed dephotolysis in emulsion nanocrystals of silver halides: I. Recombination processes at early stages of photolysis

Abstract

Early stages of formation of few-atom clusters of photolytic silver in AgBr nanocrystals are studied using the pulsed dephotolysis technique. It is shown that dephotolysis is characterized by a clearly pronounced dependence on the pulse duration of nonactinic and actinic radiations, the highest efficiency of dephotolysis being achieved for nanosecond pulses. The rate constant of recombination of free electrons with captured holes is determined (κp = (6 ± 1) × 10−9 cm3 s−1) and the dependence of the recombination rate on the level of excitation is found. The maximum recombination rate for the highest excitation level is found to be Vpmax = 109 s−1 and the surface concentration of recombination centers is determined to be Nr = (2 ± 0.5) × 1011 cm−2.