Calcination temperature optimization, energy transfer mechanism and fluorescence temperature dependence of KLa(MoO4)2:Eu3+ phosphors

The optimum calcination temperature for KLa(MoO4)2:Eu3+ phosphor was confirmed to be 1000 °C via checking the XRD patterns, SEM images and fluorescence spectra for the samples derived from solid state reaction. The energy transfer behavior between Eu3+ ions was studied. It was found that electric dipole-dipole interaction is responsible for the fluorescence quenching of 5D2 and 5D1 levels, but exchange interaction is in charge of 5D0 fluorescence quenching. It was also observed that color coordinates of the studied phosphor can be tuned when the doping concentration is relatively low. The fluorescence thermal quenching process was investigated. It was found the thermal quenching followed well crossover model. Judd-Ofelt parameters of Eu3+ in KLa(MoO4)2 were obtained, and the optical transition properties were further discussed.