Lattice dynamics, core–shell electron structure and Judd − Ofelt analysis on europium-doped Gd2O3 micro phosphors

Abstract

Various concentrations of europium-doped gadolinium oxide powders are synthesized by a high-temperature solid-state reaction method. Raman spectra of the compounds exhibited the vibrations and symmetry of monoclinic single-phase crystal formation, with the predominant monoclinic phase of Gd₂O₃ which is consistent with the XRD findings reported earlier. The core level electron emission spectra revealed the formation of highly valence-stable compound systems with shell structures corresponding to Eu³⁺ and Gd³⁺ electronic states. In-depth analysis of photoluminescence spectra with multiple emissions in the yellow–red region corresponding to transitions of ⁵D₀–⁷F₂, ⁵D₀–⁷F₁, and ⁵D₀–⁷F₀ which arise due to europium substitution brought out interesting findings of colourinescence parameters. Investigations of Judd–Ofelt parameters, mean lifetimes, radiative transition rates, and CIE coordinates revealed the compatibility of the prepared samples as the good orange-red emitter.