Efficient red luminescence from EuIII complexes with maltol: implications for devices with optoelectronic technology

Present studies explore the synthesis of innovative Europium (Eu^III) complexes with the formulation [Eu(Maltol)₃ M’], where M’ abbreviates hetero-aromatic neutral ancillary antennas of varying denticities by employing liquid-assisted grinding method. FT-IR, NMR (¹H), EDX, and elemental analyses were spectroscopic techniques used to evaluate the molecular proportions in the studied complexes and to provide a complete explication of the bonding facets surrounding the Eu^III metal. The luminescence characteristics of prepared complexes were illustrated using emission and absorption spectral measurements. Complexes’ photoluminescent characteristics under UV excitation clearly show the existence of an eminent emission peak (⁵D₀ → ⁷F₂) located at 613 nm, which is accountable for the intense red emission. P-XRD and SEM outcomes verified the crystalline pattern of the prepared complexes. The complexes can be useful in optoelectronic devices since they showed good thermal stability upto 270–290 ºC. Optical bandgap enumerated through Tauc’s curves, which lie in the range 3.31–3.70 eV reveals the suitability of these complexes in semiconductor region. The red segment of CIE color space triangle was delineated by the evaluated color coordinates and the CCT metrics were less than 3000 K. This suggests that these luminescent materials could be excellent contenders for warm illuminated sources. The evaluated branching ratio of 65% for the hypersensitive peak ⁵D₀ → ⁷F₂ make it well suitable for laser reinforcement. The luminescence performance of complexes is demonstrated by internal quantum efficiency, Judd–Ofelt intensity parameters, and sensitization mechanism. The latent fingerprints were visualized under both daylight and UV light.