Luminescence kinetics of low temperature nano ZnTiO₃:Eu³⁺ red spinel under NUV excitation

The present study discusses the synthesis and characterization of rare form of low temperature cubic spinel phase of ZnTiO₃, whose synthesis is a challenging task for researchers. Powder XRD pattern confirms the formation of single phase spinel form of ZnTiO₃ crystallizes in cubic lattice. The average crystallite size obtained from TEM analysis and Scherrer' method is about 7–8 nm. Trivalent Eu ions in host lattice are confirmed by XPS spectroscopy. Photoluminescence spectral analysis infers that ZnTiO₃:xEu³⁺ (x = 0.25%, 0.5%, 0.75%, 1%, 1.25%) nanophosphors show strong red emission corresponding to the forced electric dipole transition ⁵D₀–⁷F₂ under near UV excitation. Hypersensitive ⁵D₀–⁷F₂ transition indicates inversion antisymmetry crystal field around Eu³⁺ environment, favourable to improve red color purity. The type of multipolar interaction responsible for florescence quenching is also discussed. The color co-ordinate of all samples estimated from emission spectra is comparable to the national television standard committee value of red emission. The compositional dependence of Judd–Offlet parameters were evaluated and discussed. Eu doped spinels with defects associated structure shows better luminescent LED applications.