Structure of ''orange-luminescence'' centers in cadmium sulphide

Investigation results of polarization characteristics of luminescence spectra within 1.8-2.2 eV range and its excitation in specially non-doped as well as doped with Cu and Ag impurities cadmium sulphide are presented. It is shown that high-energy part of ''orange'' luminescence spectrum in these crystals is determined by one elementary band while the rest part of the luminescence band is presented as overlapping of different-polarization subbands. The method of polarization diagrams has been used to state that luminescence centres (donor-acceptor pairs) and excitation centres (donors of interstitial cadmium) in doped crystals form complex anisotropic centres-trimers. Symmetry of these centres determining ''orange'' luminescence in CdSiCu and CdSiAg is specified, their identification is conducted