Optical properties of SrSi₂O₂N₂:Eu²⁺ phosphor enhanced by the addition of carbonate or fluoride reactive agents

We describe powders of SrSi₂O₂N₂:Eu²⁺ green phosphor synthesized with various reactive agents in a wide range of concentration. Two approaches are described, the first is adding carbonate reactive agents (K₂CO₃ and Li₂CO₃) to the initial powders excessively and, the second, using SrF₂ reactive agent as an additional Sr source to increase the reactivity. XRD and particle size distribution analysis elucidated several additional phases in the final phosphors and revealed changes of powder morphology, including the presence of particle agglomerates. The studies of emission and excitation spectra, emission quantum efficiency and thermal quenching as well as thermoluminescence, supported by the calculations of trap depths and parameters of the electron–phonon interaction, bring a comprehensive insight into the influence of reactive agents on the SrSi₂O₂N₂:Eu²⁺ phosphor.