Versatile deep red-emitting SrCeO₃: Eu³⁺ nanopowders for display devices and advanced forensic applications

In the present study, simple solution combustion technique was employed to prepare SrCeO3 nanopowders (NPs) doped with europium ions (Eu3+) in the presence of citric acid as fuel. Various analytical techniques were utilized to explore the detailed characterization of prepared SrCeO3:Eu3+ (1-9 mol%) nanopowders. The prepared NPs showed an orthorhombic (Pmna) structure confirmed by powder X-ray diffraction (PXRD) pattern. Field emission scanning electron microscope (FESEM) micrographs confirmed the presence of emerging needle-like structures. Furthermore, the average particle size was evaluated by using transmission electron microscopy (TEM) and it was found to be -56 nm. The diffused reflectance spectra (DRS) results indicated that the energy band gap values ranged between 3.36 and 4.00 eV with a calculated refractive index varying from 0.76 to 1.34. The Photoluminescence studies were carried out for all the prepared NPs. Among the observed peaks, four prominent emission peaks centred at 540 nm (D-5(0)-> F-7(0)), 555 nm (D-5(1)-> F-7(2)) 592 nm (D-5(0)-> F-7(1)), and 612 nm (D-5(0)-> F-7(2)) were observed under 469 nm (F-7(0)-> D-5(2)) excitation wavelength with a dominating electric dipole transition D-5(0)-> F-7(2), confirming with dipole-dipole transition. Further, the colour properties of the prepared NPs were studied by means of chromaticity plots. Commission International de I'Eclairage (CIE) diagram reveals the red emission of the prepared NPs with coordinates (0.63, 0.34), the calculated colour temperature (CCT) was found to be -2326 K, and average quantum efficiency was found to be -46%. The obtained fingerprint results acknowledge the detection of three levels of ridge patterns viz., central arch, ridge end (type-I), bifurcation, cross over (type-II), and sweat pores (type-III). All the obtained results recommend using prepared nanopowders in fabricating display devices as an efficient red component and in advanced forensic applications.