Excitation density effects in luminescence properties of CaMoO4 and ZnMoO4.

The effect of the self-trapped excitons interaction under dense laser excitation was studied in ZnMoO 4 and CaMoO 4. The interaction results in the quenching of exciton's luminescence and in the non-exponential character of decay kinetics. The threshold values of exciton's concentration in the crystals for the quenching effect are determined. The generalized quenching model, which accounts for thermal quenching of excitonic emission and excitons mobility has been developed. The model has been applied for numerical simulation of the experimental data and allowed to obtain the parameters of dynamics (diffusion) and interaction (radius of the dipole-dipole interaction) of self-trapped excitons with account for 3D nonuniform distribution of the initial concentration of excitations. • Excitons interaction is studied in CaMoO 4 and ZnMoO 4 under dense laser excitation. • The liminal concentrations of excitons for observation of their interaction were determined. • The generalized quenching model of excitons interaction was developed. • The interaction radii R d-d are calculated from the data of Z-scan and decay curves. [ABSTRACT FROM AUTHOR]