Optical transmission spectra of a silicate glass containing nanocristallites of cadmium sulphoselenide

The optical transmission spectra of CdSe(x)S(1-x) doped low viscosity silicate glass are experimentally studied. Glass samples were subjected to one- or multi-step heat treatment for different lengths of time. We have followed the modification of the absorption spectra after each heat treatment. The red shift of the absorption edge and the accompanying change of coloration from orange to red are explained by size-quantization effects in the energy spectrum of electrons and holes in semiconductor nanoparticles thermally developed in low viscosity glass matrix. X-ray diffraction data show no stoichiometry changes during the heat treatment processes. Crystallites composition derived from the diffraction peaks was very close to the value estimated from the position of absorption edge.