Structural and Optical Properties of Ce ³⁺ Ion Incorporation in a KMgCaF ₃ Phosphor

This study investigates the structural and photoluminescent behavior of Ce3+-doped KMgCaF3 phosphors prepared by using a solid-state reaction. X-ray diffraction (XRD) and photoluminescence (PL) spectroscopy were employed to analyze the impact of Ce3+ incorporation on the host lattice. XRD analysis identified a perovskite structure exhibiting minor lattice distortions attributed to Ce3+ substitution. Fourier transform infrared spectroscopy was utilized to detect the distinct vibrational modes associated with functional groups present in the phosphor matrix. PL analysis revealed an enhanced luminescence band at 651 nm due to 5d–4f transitions of Ce3+ ions excited at 370 nm. UV–vis spectroscopy showed that the band gap was tunable from 3.83 eV (undoped) to 4.15 eV (1–3 mol %) and decreased to 3.35 eV at 5 mol %, attributed to quantum confinement and defect-induced states. The Commission International Del’Eclairage (CIE) chromaticity coordinates effectively validated the precision and stability of the light’s color output, highlighting its excellent purity and consistent emission profile. These findings suggest that KMgCaF3:xCe3+ holds significant promise for deployment in solid-state lighting and photocatalytic systems.