Emission spectra of microcrystalline CdS doped in sol-gel derived glasses

CdS crystals with average sizes of 4-6 nm were precipitated in SiO 2 and 1.4Na 2 0.20-8ZrO 2 . 77.8SiO 2 glasses by reacting the sol-gel derived glasses with H 2 S gas. Emission spectra, measured with CdS doped SiO 2 glasses stored in air and CdS doped 1.4Na 2 0.20-8ZrO 2 . 77-8SiO 2 glasses heated in both air and H 2 -N 2 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 1.4Na 2 0.20-8ZrO 2