Luminescence studies and Judd Ofelt parameterization of Dy³⁺ activated La₂(WO₄)₃ yellow phosphor

The synthesis and detailed luminescence studies of a series of La_2-xDy_x(WO₄)₃ (x = 0.02, 0.1, 0.2, 0.4, 0.6, 0.8) phosphors synthesized via microwave-assisted co-precipitation technique is reported in this paper. The XRD analysis confirmed that the phosphors were crystalized in a monoclinic structure with space group C2/c and FTIR analysis identified the characteristic vibrational modes. Morphological studies were conducted using FESEM analysis, and the EDS technique substantiated the effective incorporation of Dy³⁺ ions in La₂(WO₄)₃. The photoluminescence excitation and emission spectra of varying concentrations of Dy³⁺ ions were recorded and an optimum concentration of 10% exhibited the highest intensity. The emission spectra of all phosphors were dominated by peaks at 484 nm and 574 nm. The radiative properties were evaluated using Judd-Ofelt analysis and the JO intensity parameters followed the trend Ω₂ > Ω₆ > Ω₄. The gradual decrease in the decay lifetime value of ⁴F_9/2 excited level with an increase in doping concentration elucidates concentration quenching phenomena due to dipole – quadrupole interaction. The emission data were also analyzed by calculating CIE coordinates and concluded that Dy³⁺ doped La₂(WO₄)₃ phosphors have potential applications in yellow light generation.