Stability and optical properties of dispersions of CdS, ZnS, and Ag2S nanoparticles synthesized in microemulsion

Abstract

CdS, ZnS, and Ag2S nanoparticles have been synthesized in microemulsion. The synthesis of nanoparticles depend on the composition of the reaction medium and on the proportions of the precursors. The phase diagram for sedimentation stable dispersion of the nanoparticles synthesized in microemulsion has been determined. The region of the stable nanoparticle dispersion is much smaller than the region of the inverse microemulsion in the n-heptane-AOT-H2O system. The UV-vis absorption and photoluminescence spectra of the CdS, ZnS, and Ag2S nanoparticles have been investigated. The size of the nanoparticles increases with an increase in droplet size in the microemulsion, and this shifts the exciton peaks.