RADIATIVELY INDUCED MODIFICATION OF THE L UMINESCENCE SPECTRUM OF THEION CE3-SOLUTION CA1-XSRXS( IN THE SOLID)

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 lum inescence spectrum of these phosphors under interband excitation consi sts of two spectra: the first one is the same as for the activator exc itation and the second one with identical course but shifted towards l onger wavelengths. The latter spectrum is attributed to the portion of Ce3+ centres in lattice sites with radiatively induced modification o f symmetry. This effect was also considered for X-ray excitation. The proposed model allows to obtain new information on the spatial structu re of Ca1-xSrxS solid solutions.