Preparation of ZnSe quantum dots embedded in SiO2 thin films by sol–gel process

In this paper, ZnSe quantum dots embedded in SiO2 thin films was successfully prepared with H2SeO4 as selenium source and Zn(Ac)2·H2O as zinc source by a sol–gel process. Reaction mechanism of synthesizing ZnSe nanocrystallites embedded in silica thin films also was discussed through the XRD and DTA–TG analysis. In the process of synthesizing ZnSe nanocrystallites, ZnSeO4·H2O crystallites precipitated in organic solvent was prepared first, then the crystallites were reduced with carbon monoxide atmosphere. The XRD analysis reveals the structure of ZnSe phase is sphalerite (cubic ZnS). XPS results show that the atomic ratio of Se/Zn was smaller than the nominal atomic ratio of the sample, which means the selenium element was volatilized seriously. The AFM images show that the size of ZnSeO4 crystallite was increased with the concentration of selenium element. This approach to synthesis of ZnSe nanocrystallites has the potential application in the preparation of optical composite thin films from sol–gel process.