Abstract: Silver nanoparticles were synthesized by the method of γ-irradiation in the water-in-oil (w/o) microemulsion composed of SDS (sodium dodecyl sulfate), n-hexanol, cyclohexane and aqueous solution. Light emission in different formation stages was observed, and we found that in our case it was mainly the clusters but not nanoparticles that caused the photoluminescence, with the proof from the absorption spectra and transmission electron microscope (TEM). And it was also suggested that electron and/or hole states can be perturbed by surface states, as indicated by the dependence of the emission spectrum on the nature of the surface. Silver nanoparticles can self-assemble to form the superlattics due to the very narrow size distribution.

Key words: Photoluminescence, Silver, Nanoparticle, Cluster, γ-irradiation