ИСТИНА

The aim of the presentation is the study of interaction of excitons at their high concentration in crystals with oxyanionic type of excitons, viz in molybdates. It is known that the decay profile and the emission intensity of excitons depend on excitation density due to the interaction of excitons. The quenching reveals in the non-exponential character of decay kinetics and in the dependence of STE light yield with variation of the density of laser irradiation. This variation is controlled by the translation of the sample along the axis of the focused laser beam - so called z-scan experiment. In the present study we have combined these two experimental approaches for development of model of interaction of exciton. Non-linear quenching of luminescence for the studied crystals begins for concentration of excitations above 1020 per cm3. A prominent increase of the fast initial part of decay curve was detected with the further increase of the excitation density. The simulation of the measured decay and z-scan curves is performed in order to get information about the parameters of dynamics (diffusion, localization rate) and interaction (radius of the dipole-dipole interaction) of STEs in ZnMoO4 and CaMoO4.