2024-02-152024-02-152018MAIA, Lauro J. Q. et al. Luminescent Eu 3+ doped Al 6 Ge 2 O 13 crystalline compounds obtained by the sol gel process for photonics. Optical Materials, Amsterdam, v. 75, p. 297-303, 2018. DOI: 10.1016/j.optmat.2017.10.038. Disponível em: https://www.sciencedirect.com/science/article/pii/S0925346717306717. Acesso em: 7 jan. 2024.0925-3467e- 1873-1252https://www.sciencedirect.com/science/article/pii/S0925346717306717We synthesized pure and Eu3+ doped Al6Ge2O13 samples by an easy and low-cost sol-gel route using the GeO2, Al(NO3)3·9H2O and Eu(NO3)3·6H2O as precursors, tetramethylammonium hydroxide and ethanol as solvents. The Al6Ge2O13 crystalline phase possesses orthorhombic structure and is a potential host for rare earth ions, especially due to high aluminum concentration. Homogeneous and transparent sols and gels were obtained. The samples containing 1 mol% of Eu3+ were heat-treated at 1000 °C to eliminate organic compounds, providing high optical quality and structural purity. All materials were characterized by thermogravimetric and differential thermal analysis, X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electron microscopy, selected area electron diffraction, diffuse reflectance spectra in the ultraviolet–visible–near infrared regions and photoluminescence measurements. High purity of Eu3+ doped Al6Ge2O13 orthorhombic phase and well crystallized grain dimensions of around 100 nm was obtained with high red photoluminescence emission. The decay lifetime of 5D0 level from Eu3+ (the emission at 612 nm) was determined, being between 0.97 and 2.12 ms, and an average quantum efficiency of 54% was determined (considering the average experimental lifetime of 1.77 ms). Moreover, it was calculated and analyzed some parameters of Judd-Ofelt theory applied to Eu3+ emissions from Al6Ge2O13 host. The results show that Eu3+ doped Al6Ge2O13 crystalline compounds have large potential to be used in displays and LED devices.engAcesso RestritoAl6Ge2O13 crystalline phaseEu3+ dopedStructural propertiesOptical propertiesArtigo10.1016/j.optmat.2017.10.038