The features of energy transfer to the emission centers in ZnWO4 and ZnWO4:Mo

•Mo impurity perturbs energy transfer to intrinsic emission centers at 300 K.•Holes self-trapping at WO66− suppress emission of MoO6 centers at T<60 K.•Modeling of the energy transfer process to intrinsic emission centers is presented.•Onsager sphere radius and thermalization length for ZnWO4 are calculated.

The process of energy transfer to the emission centers is studied in ZnWO4 and ZnWO4:Mo single crystals in the temperature range 10-300 K. A numerical simulation describing the process is presented; the temperature dependence of energy transfer efficiency to the intrinsic emission centers in ZnWO4 is shown to be defined by the modification of Onsager sphere radius. A competitive role of radiative relaxation channel related to the impurity of molybdenum is studied in ZnWO4:Mo. It is shown that below 60 K the energy transfer to the MoO6 emission centers by free charge carriers terminates due to the self-trapping of holes at WO6 complexes.