UV-Absorption Observation of the Silver Bromide Growth from a Single Molecule to the Crystal in Solution

Pulse radiolysis is used to study the formation of the AgBr molecule and the (AgBr) 2 dimer in solution. A short time (400 ns) after the nanosecond pulse, the kinetics of AgBr molecule formation is observed at 295 nm. The monomer signal decays to give the dimer (AgBr) 2 . The dimer spectrum is shifted to the blue and the maximum is at 285 nm. The nanometric (AgBr) n clusters have been synthesized by γ-radiolysis. The final size of the clusters can be controlled by the irradiation dose and dose rate. The direct exciton band of AgBr clusters shifts to the red as their size increases. The splitting energy (which is the difference between the energy of the direct exciton band and the energy of the splitting band) and the intensity ratio of the two bands change with the size of AgBr nanoclusters.