The effect of boron and scandium doping on the luminescence of LuAG:Ce and GdAG:Ce for application as scintillators

This study concerns cerium and boron doped Lu₃Al₄Sc₁O₁₂ and Gd₃Al₃Sc₂O₁₂ garnet µ-crystalline powders, which were synthesized for the first time. Rare earth ion, particularly Ce³⁺ activated garnets, due to their high density and efficient Ce³⁺ luminescence upon blue, UV, or x-ray excitation, can be used as scintillators that convert high-energy radiation into visible light. The incorporation of B³⁺ and Sc³⁺ ions into the garnet matrix corresponds to the improvement of the scintillating properties. Boron in these compounds could act like a flux and thus modulate particle morphology, while scandium solely changes the physical and luminescent properties of these garnets. From the measured radioluminescence emission spectra, it could be concluded that boron doping results in a higher emission intensity when the compounds are excited by high-energy radiation. The most striking effect is that the decay time is reduced, and the quantum efficiency of the compounds increases. After improving the kinetic properties of these compounds, it is possible to discuss a wider application of the synthesized materials. In addition to the aforementioned properties, room temperature as well as temperature dependent photoluminescence emission, excitation, and decay times at different temperatures were taken for all samples. The elemental composition of the samples was determined by using the ICP-OES technique. The crystal structure was analyzed by means of powder XRD. Particle morphology and size distribution were also investigated. The main idea of this research is to synthesize new and adjusted garnet type compounds that show better luminescent properties, which are required for scintillator materials.