A New Ultrafine Luminescent La₂O₃:Eu³⁺ Aerogel

This paper reports on the synthesis and characterization of La₂O₃:Eu³⁺ luminescent aerogels fabricated by the sol-gel method and the supercritical drying technique. The % mol concentration of the Eu³⁺ ion was varied to study the effects on the luminescent properties of the aerogels. XRD and TEM analysis showed that the La₂O₃:Eu³⁺ aerogels exhibited a semi-crystalline behavior regardless of whether the concentration of europium was increased. SEM micrographs revealed a porous structure in the aerogels, which were composed of quasi-spherical nanoparticles that were interconnected and formed coral-shaped agglomerates. Photoluminescence spectroscopy characterization showed that the aerogels had an infrared emission located at λ = 793 nm, and the maximum photoluminescence emission intensity was observed for the aerogel with 50% Eu³⁺. The results demonstrate that, without heat treatment, it is possible to manufacture luminescent aerogels of rare-earth oxides that can be used in opto-electronic devices.