Structural Characterization of Colloidal Ag₂Se Nanocrystals

Abstract

Ag2Se nanocrystals of less than 15 nm have been investigated by means of high-resolution electron microscopy and nano-energy-dispersive X-ray spectroscopy. Two groups of clusters are distinguished, depending upon their preparation technique. Those obtained by double jet precipitation show a limited stability both in time and under the electron beam. Their structure is orthorhombic, although a cubic phase is encountered if an excess Ag is present. Those prepared by microemulsion mixing have an orthorhombic structure as well but show a greater stability.