NON-EXPONENTIAL ZnS:Mn LUMINESCENCE DECAY DUE TO ENERGY TRANSFER.

In some recent papers it was shown that for the ZnS:Mn luminescence at high Mn concentrations c//M//n the energy transfer between the various centers is important. In the present paper it is shown that the observed nonexponentiality of the decay of the yellow emission band in ZnS:Mn can be explained quantitatively in dependence on the Mn concentration on the basis of the energy transfer model. In the past the nonexponential decay of this emission band measured in photo- or electroluminescence was ascribed to the occurrence of n-atomic Mn clusters (n equals 2, 3, 4) at higher c//M//n which were assumed to have decreasing radiative lifetimes with increasing n.