RADIATIVELY INDUCED MODIFICATION OF THE LUMINESCENCE SPECTRUM OF THE ION CE3+ IN THE SOLID-SOLUTION CA1-XSRXS

Differences in the emission spectra of the Ce3+ ion in Ca1-xSrxS solid solutions, measured under excitation in the activator band and in the fundamental absorption region are explained. It is shown that the luminescence spectrum of these phosphors under interband excitation consists of two spectra: the first one is the same as for the activator excitation and the second one with identical course but shifted towards longer wavelengths. The latter spectrum is attributed to the portion of Ce3+ centres in lattice sites with radiatively induced modification of symmetry. This effect was also considered for X-ray excitation. The proposed model allows to obtain new information on the spatial structure of Ca1-xSrxS solid solutions.