A novel path of luminescence for aerogels using TTA on the Er₂O₃/Eu₂O₃ system

This article reports on the properties of xerogel and aerogels of rare-earth with a hybrid matrix corresponding to the TTA/Er₂O₃/Eu₂O₃ system synthesized through the sol-gel method and the technique of supercritical drying at low temperature and characterization. A variant of the sol-gel method employing epoxide-assisted gelling and supercritical drying with CO₂ was used, due to the efficiency and the fact that it can remove the solvent from the gels and yield ultra-porous materials. The morphology of TTA/Er₂O₃/Eu₂O₃ powders consist of agglomerates of irregularly shaped particles ranging from 100 nm to 1 μm in size. The use of the organic compound TTA does not change the cubic crystalline structure of the Er₂O₃:Eu₂O₃ powders. The results show a visible emission starting at a concentration of 2% when the material was excited to a wavelength of 613 nm, indicating a highly efficient energy transfer between the matrix and the rare earth which can be attributed to smaller crystal size and a large surface area. Due to the improvement of their spectroscopical properties, the hybrid powders are promising for use as sensors in medical and photoelectronic applications.