Interaction of radiation-induced defects of glasses with CdSe and CdS nanocrystals

The influence of X-ray irradiation on the absorption spectra of commercial light filters based on the glasses containing selenium, cadmium, and sulfur has been investigated. The light filters were preliminary subjected to the heat treatment, which resulted in the precipitation of nanocrystals in the glass matrix. The irradiation leads to stationary partial bleaching of glasses. Analysis demonstrates that the difference spectra contain the induced absorption bands of conventional radiation-induced color centers of alkali silicate glasses and a fine structure. The fine structure closely resembles the known difference spectra obtained under the action of the external constant or low-frequency alternating electric field on glasses containing CdSe nanocrystals. The conclusion is drawn that the stable radiation-induced centers of the glass at the interface with nanocrystals serve as a source of the Coulomb field affecting the energy levels of the size quantization of the nanocrystals. It is suggested that nanocrystals of the type of the CdS_xS_1−x solid solutions in these glasses are either lacking or do not manifest themselves in the spectra after irradiation.