Spectroscopic Investigation of Optical Properties in Ca_0.5MgAl₃O₆: Eu³⁺, Dy³⁺, and Tb³⁺ Phosphors

The article investigates optical properties of Ca_0.5MgAl₃O₆: Eu³⁺, Dy³⁺, and Tb³⁺ (x = 0.5, 0.7, 1.0, 1.3, and 1.5 mol%) novel phosphors synthesized by the simple combustion method. The XRD spectra were matched successfully with the standard JCPDS database file no. 9002506, and refinement data confirm the hexagonal phase of the Ca_0.5MgAl₃O₆ matrix. Under near-ultraviolet light excitation, the Eu³⁺-doped phosphor shows emission peaks at 593 and 618 nm, whereas the Dy³⁺-doped Ca_0.5MgAl₃O₆ phosphor shows the emission peaks at 486 and 547 nm. In the case of Tb³⁺ ions, the emission peak is at 491 and 546 nm. The concentration quenching phenomenon was observed at x = 1.0 mol%. The structural properties were investigated using characterization techniques such as the Rietveld refinement, FTIR, and UV-visible spectroscopy. The morphology was determined using the FE-SEM, and the elemental composition was verified using the EDS. The average particle size determined using the ImageJ software is 52.46 nm. The CIE chromaticity diagram confirms the multicolor light emission characteristics of the Ca_0.5MgAl₃O₆ matrix, and it has good caliber for use as RGB phosphor and solid-state lighting applications.