Luminescence properties of layered mixed-anion compounds Sr2ScCuSeO3 and Sr3Sc2Cu2Se2O5

We report the synthesis and luminescence properties of new layered mixed-anion compounds, Sr2ScCuSeO3 and Sr3Sc2Cu2Se2O5. Sr2ScCuSeO3 and Sr3Sc2Cu2Se2O5 were synthesized by solid-state reaction and were investigated using x-ray diffraction, diffuse reflectance, and photoluminescence spectroscopies. Both compounds have very similar properties except for their optical band gaps and emission peak energies. At room temperature, Sr2ScCuSeO3 and Sr3Sc2Cu2Se2O5 exhibit optical band gaps energies of 2.9-3.0 eV. The excitonic luminescence with very fast emissions of similar to 30 ps were observed in both compounds even at room temperature. This feature of the compounds makes them suitable for fast scintillator applications. Our results suggest that the luminescence properties such as emission peak energies and lifetimes of these layered mixed-anion compounds can be controlled by changing their structure and composition.