Sol-gel preparation and luminescent properties of Eu3+ doped Al2O3 hollow microspheres

Rare earth elements have attracted significant attention due to their unique electronic structure. By doping rare earth ions into oxides, they can be used as spectral conversion materials in fields such as photovoltaic power generation and biological probes. In this paper, the performance of Eu 3+ doped Al 2 O 3 hollow microspheres by sol-gel method was analyzed by SEM, XRD, IR, TG-DSC, and fluorescence spectrometer. Using aluminum isopropoxide (Al(OC 3 H 7 ) 3 ) as raw material, PMMA with a particle size of 150 nm as the template, PMMA/boehmite particles with core-shell structure can be prepared by sol gel method and template method. After adding Eu 3+ and heat treatment, a transition occurred from γ-AlOOH(85 °C)→γ-Al 2 O 3 (600 °C)→θ-Al 2 O 3 (1000 °C)→α-Al 2 O 3 (1200 °C) as the temperature increased, and EuAlO 3 was generated at 1200 °C. Eu 3+ occupied the sites without inversion centers inside the host lattice, and the alumina was an effective matrix for the fluorescent properties of Eu 3+ . Its excitation was caused by the 7 F 0 → 5 L 6 transition, and its luminescence was controlled by the 5 D 0 → 7 F 2 transition, which can convert ultraviolet light into red and orange light. The fluorescence intensity increases with the increase of Eu 3+ content, and no quenching was observed at a doping concentration of 10mol% Eu 3+ .