Redistribution of electronic excitation energy in impurity crystals

A model which permits obtaining kinetic law for excitation decay in the presence of clusters of impurity ions of arbitrary length in a dielectric crystal matrix is proposed. The phenomenon of electronic excitation trapping in impurity paired centers (PCs) in doped dielectric crystals is investigated by using the theory of the Markovian processes. It is shown that the delay of excitation lifetime in PCs can exert a vital influence on the kinetics of excitation decay in the whole impurity subsystem. The dependences of excitation lifetime on the concentration of impurity ions and pump power are found.