Photoluminescence imaging of europium (III)‐doped γ‐Al2O3 nanofiber structures

Aluminium oxide (Al₂O₃) has widely been used for catalysts, insulators, and composite materials for diverse applications. Herein, we demonstrated if γ‐Al₂O₃ was useful as a luminescence support material for europium (Eu) (III) activator ion. The hydrothermal method and post‐thermal treatment at 800°C were employed to synthesize Eu(III)‐doped γ‐Al₂O₃ nanofibre structures. Luminescence characteristics of Eu(III) ions in Al₂O₃ matrix were fully understood by taking 2D and 3D‐photoluminescence imaging profiles. Various sharp emissions between 580 to 720 nm were assigned to the ⁵D₀→⁷F_J (J = 0, 1, 2, 3, 4) transitions of Eu(III) activators. On the basis of X‐ray diffraction crystallography, Auger elemental mapping and the asymmetry ratio, Eu(III) ions were found to be well doped into the γ‐Al₂O₃ matrix at a low (1 mol%) doping level. A broad emission at 460 nm was substantially increased upon higher (2 mol%) Eu(III) doping due to defect creation. The first 3D photoluminescence imaging profiles highlight detailed understanding of emission characteristics of Eu(III) ions in Al oxide‐based phosphor materials and their potential applications.