Optical anisotropy of red luminescence centers in CdS irradiated with thermal neutrons

We have investigated the red luminescence spectrum (lambda/sub max/ = 730 nm at 770K), and the excitation and photocurrent spectra of CdS which had been irradiated with thermal neutrons. We have also studied the polarization characteristics of these spectra (the degree of spontaneous polarization in the luminescence and the excitation, and polarization diagrams). Luminescence polarization was used to find the orientation in the lattice of the optical dipoles; for two basic luminescence bands the dipoles are oriented at 700 and 00 relative to the axis of the crystal. A microscopic model is constructed for two anisotropic luminescence centers in thermal-neutron irradiated cadmium sulfide