PHOTOLUMINESCENCE OF A SILVER-DOPED GLASS

The absorption, emission and excitation spectra of Ag+ ions in a soda lime glass doped with two different concentration of silver are invest igated. Absorption spectra exhibit a main broad band peaked at about 2 60 nm (4.77 eV) with a shoulder at about 227 nm (5.46 eV). The relativ e height of the shoulder depends on silver concentration in the glass. Emission spectra of Ag+ are dominated by an ultraviolet broad band at about 330 nm (3.76 eV). The excitation spectra for this emission show a preponderant broad band peaked at about 227 nm (5.46 eV) which coin cides with peak position of the shoulder displayed in the optical abso rption spectra. A weak broad featureless emission band centred at abou t 550 nm (2.25 eV) with an excitation peak at about 242 nm (5.12 eV) i s tentatively related to an impurity from the host silica glass rather than originated in silver-type centres. Comparison of the luminescenc e decay curves for both emissions show substantial differences between them. Consequently, the emissions in the time-resolved spectra can ea sily be discriminated.