Europium-doped strontium gadolinium oxide phosphor: Investigating structural and photoluminescence characteristics...

SrGd₂O₄ phosphors doped with Eu³⁺ were successfully synthesized through a sol-gel combustion method, covering a range of dopant concentrations from 0.25 mol% to 3 mol%. The structural analysis of these phosphor materials was comprehensively conducted utilizing various techniques, including X-ray powder diffraction analysis (XRD), Energy Dispersive X-ray (EDX), and Fourier-transform infrared spectroscopy (FTIR). In addition to unveiling the structural characteristics, these analyses provide valuable insights into the compositional aspects, enhancing our understanding of the synthesized SrGd₂O₄:Eu³⁺ phosphors across different doping levels. XRD analysis findings validate the successful generation of the intended SrGd₂O₄ host, demonstrating orthorhombic system structures consistent with JPCD card number 98-019-3592. FTIR analyses conducted on the phosphor samples not only identify bending modes but also reveal intricate details about small vibration bonds within the material. When excited by the 349 nm laser, SrGd₂O₄:xEu³⁺ phosphors exhibit distinct photoluminescence (PL) properties like red emission at 614 nm from Eu³⁺. From the emission spectra, one can clearly observe that Eu³⁺ with an ionic radius close to the Gd³⁺ ion preferentially occupies the symmetry sites of the host lattice. The optimal doping concentration was determined to be 0.5 mol%, as revealed by the data in our study. Additionally, a deeper understanding of the luminescence quenching mechanism was attained, pinpointing the involvement of dipole-dipole (d-d) energy transfer in this intriguing phenomenon. This optimal concentration not only enhances the material's properties but also underscores the pivotal role of d-d interactions in governing the luminescence behavior within the doped system.