Phosphorescence decay and thermoluminescence of ZnS: (Ag, Ce) and ZnS: (Cu, Ce) phosphors

Investigation of luminescence and scintillation properties of a ZnS–Ag/6LiF scintillator in the 7–295K temperature range

“…The holes are then trapped by Ag þ which replaces regular Zn 2 þ ions on their sites, while electrons can be captured by shallow levels of charge-compensating sites associated with either impurities or intrinsic defects. Subsequent recombination of electrons with these holes results in the characteristic blue emission of ZnS-Ag phosphor [6][7][8][9][10][11][12]. The decrease of temperature results in an increase of the emission intensity that is a typical feature of recombination luminescence.…”

“…The mechanism behind the intense emission band at 450 nm is now well established as being due to to recombination of spatially separated donor-acceptor pairs. A characteristic feature of such recombination luminescence is a long decay time, spanning the range from milliseconds to a few seconds [11,12].…”