Quenching, Stimulation, and Exhaustion Studies on Some Infrared Stimulable Phosphors

As a continuation of earlier work on the two phosphor systems SrS: Ce, Sm and SrS: Eu, Sm, studies of the quenchings and the enhancements of fluorescent emission by visible and infrared radiation have been made. Two stimulation bands have been measured and the relative efficiencies of exhaustion and of stimulation of visible emissions by the two bands have been studied. These data have been correlated with the simplified band-theory model that had been proposed earlier. The measurements indicate that the two stimulation bands are associated with the same center. This can be represented by the assignment, to that center, of two energy levels within the energy gap.