Luminescent Properties of Eu3+-Doped Hybrid SiO2-PMMA Material for Photonic Applications

Hybrid organic-inorganic materials are of great interest for various applications. Here, we report on the synthesis and optical characterization of silica-PMMA samples with different Eu3+ molar concentrations. The optical properties of this material make it suitable for photonic applications. The samples were prepared using the sol-gel method, mixing tetraethyl orthosilicate (TEOS) as a silica glass precursor and methyl methacrylate (PMMA) as a polymer component. Europium nitrate pentahydrate was then added in six different molar concentrations (0.0, 0.1, 0.25, 0.5, 0.75, and 1%) to obtain as many different samples of the material. The absorption spectra were obtained applying the Kubelka-Munk formula to the diffuse reflectance spectra of the samples, all in the wavelength range between 240 and 2500 nm. The emission and excitation measurements were made in the visible range. Five bands could be identified in the emission spectra, related to electronic transitions of the ion Eu3+ (D-4(0) -> F-7(i), i from 0 to 4). In the excitation spectra, the following bands were detected: F-7(0) -> (5)G(3) (379 nm), F-7(0) -> (5)G(2) (380 nm), F-7(0) -> L-5(6) (392 nm), F-7(0) -> D-5(3) (407 nm), F-7(0) -> D-5(2) (462 nm), and F-7(0) -> D-5(1) (530 nm). The emission decay times were measured for the different samples and showed an inverse dependence with the Eu3+ concentration.