EMISSION-SPECTRA OF MICROCRYSTALLINE CDS DOPED IN SOL-GEL DERIVED GLASSES

CdS crystals with average sizes of 4-6 nm were precipitated in SiO2 and 1.4Na2O.20.8ZrO2.77-8SiO2 glasses by reacting the sol-gel derived glasses with H2S gas. Emission spectra, measured with CdS doped SiO2 glasses stored in air and CdS doped 1.4Na2O.20.8ZrO2.77.8SiO2 glasses heated in both air and H-2-N2 gas, show a sharp band at 500 nm due to the recombination of electrons and holes via the donor or acceptor level, and a broad band around 650 nm arising from sulphur vacancies at the crystal surface. On the other hand, CdS doped 1.4Na2O.20.8ZrO2. 77.8SiO2 glasses which were heated at 700-degrees-C in H2S-N2 gas showed only the short wavelength emission but no band at long wavelength. The emission decay time and third order nonlinearity were measured for the CdS doped 1-4Na2O.20.8ZrO2.77.8SiO2 glasses which had the different emission characteristics.