Probing the Judd Ofelt parameters and photometric attributes of Eu3+- activated Ca9Y(VO4)7 nanomaterials for emerging lighting applications

Eu³⁺ activated Ca₉Y(VO₄)₇ nanomaterials radiating bright-red light were generated via a rapid, efficient, and ecological solution combustion technique. Rietveld refinement of XRD patterns confirmed the trigonal structure including R3c (161) space group of generated crystalline nanophosphors. Energy dispersive X-ray (EDAX) analysis determined the composition of elements present in the targeted samples and electron microscopy (SEM and TEM) determined the non-uniform agglomerated particles lie in nano-domain (1–100 nm). Tauc’s hypothesis was utilized to calculate the band gap. The presence of an intense band at 330 nm in the excitation spectrum, has certified the energy transfer between VO₄³⁻ → Eu³⁺ ions. A detailed examination of PL (Photoluminescence) emanation spectra was accomplished to calculate the Judd–Ofelt (J–O) parameters. The bright-red light in the targeted nanophosphors is observed from the ⁵D₀ → ⁷F₂ radiative transition. Dexter’s theory and the Inokuti-Hirayama (I-H) model were applied to confirm the dipole–dipole (d–d) type of interlinkages as a real phenomenon for concentration quenching. Moreover, the optical characteristics of Ca₉Y_0.6Eu_0.4(VO₄)₇ nanophosphor including high quantum efficiency (65.70%), CIE coordinates (0.4137, 0.3985), and color temperature (3383 K) showed their applications in wLEDs, visible color emitting photonic devices, advanced lasers, sensors, aircraft-components, and in other display devices.