Analysis of fluorescence properties of novel Eu³⁺-doped ZnAl₂O₄-based ceramic aerogels for high-power optical device applications

A novel series of ZnAl₂O₄:Eu³⁺ aerogels (ZAE) and mullite ceramic phase reinforced ZnAl₂O₄:Eu³⁺ aerogels (MZAE) with high fluorescence thermal stability have been firstly synthesized for the encapsulation of high-power optical devices. However, due to the intrinsic structural brittleness of the aerogel, the structure of ZAE tends to collapse during the heat treatment and the fluorescence performance falls short of expectations. To this end, we propose a simple and effective strategy to enhance the structural rigidity of fluorescent aerogels by introducing the mullite ceramic phase into the network structure of ZAE. This can effectively suppress the agglomeration of Eu³⁺ caused by the collapse of the structure during the heat treatment, thus enhancing the optical properties of the aerogel. Compared with ZAE, MZAE has higher fluorescence thermal stability. The fluorescence intensity of MZAE at 498 K is still 75 % of that at 298 K, and the chromaticity shift is only 22 × 10⁻³.