Abstract:

The sol-gel process has been applied successfully to the preparation of small-sized CdS-doped silica glasses. Silica glasses containing 0.887.4wt% CdS were synthesized in a process in which ethylene diamine tetra-acetic acid (EDTA) or surfactant microenmulsion is added to obtain smaller size CdS crystal with narrower size distribution. These additives can be removed after the heat treatment during the densification procedure. The optical absorption edge of CdS crystals in doped glasses obtained by new methods exhibited larger blue shifts(comparing with the bulk absorption edge value of CdS crystal) than that without addition of EDTA or surfactant microemulsion in the preparing process. Thus the quantum size effect was found to be enhanced for glasses containing CdS prepared by the improved sol-gel process.

Key words: Quantum dot glass, Nanocomposite, Sol-gel process, Quantum size effect