SrNb₂O₆: Dy³⁺: a single phase warm white light emitting phosphor for solid-state lighting

The present article inspects the structural and optical properties of Dy³⁺ activated SrNb₂O₆ phosphors for solid state lighting applications. The structural properties are studied by XRD, FTIR, XPS and Raman spectroscopies. XRD data are further utilized to perform Rietveld refinement and model the structure. The band gap of the samples is evaluated to ensure the utility and found to decrease upon incorporation of the Dy³⁺ ions. The photoluminescence excitation spectra recorded at an emission wavelength of 572 nm shows several excitation peaks in the near-UV region. Afterward, the excitation wavelengths of 350, 366 and 387 nm are utilized to excite the sample, and emission spectra are recorded. The luminescence intensity is optimized in terms of Dy³⁺ concentration and the optimum luminescence is derived at 4 mol% Dy³⁺ concentration. The calculated decay times are evaluated for different energy levels and are observed to reduce on increasing doping concentration. Photometric studies reveal the CIE color coordinates in the yellowish–white region and CCT values less than 5000 K. The derived outcomes recommend the utilization of prepared phosphor materials as a single-phase warm white light emitting candidate for solid-state lighting for indoor appliances and display devices.