Rare-earth (RE) doped oxyfluoride glass-ceramics possess interesting optical properties with application in telecommunications and optoelectronics. These materials combine the transparency and mechanical and chemical resistance of aluminosilicate glasses with the low phonon energy and facile incorporation of RE ions in the fluoride crystals. The incorporation of RE ions in the fluoride crystalline phases enhances the optical emission intensity, a major property of these materials. Nanocrystallisation in different oxyfluoride glasses in the system SiO2-Al2O3-Na2O-K2O-LaF3/YF3/LuF3 is under study including thermal, structural and optical characterization.

Optical fibers with glass-ceramic core are being developed as well as laser printed wave-guides. The final aim is to optimize the direct and/or energy conversion (up and/or down-conversions) emissions for optoelectronic and biomedical applications (lasers, optical amplifiers, fiber and thin film sensors, etc.).


Another research line is the preparation of phosphorescent glass-ceramics. A variety of silicate phases doped with rare-earth ions are studied with the objective of obtaining persistent phosphor materials. In particular, Sr2MgSi2O7 presents very long after glow properties when doped with Eu/Dy ions. The mechanism of persistence has not been completely understood yet. There have been some experimental suggestions about the correlation of the persistent luminescence mechanism of phosphors with host lattice defects such as oxygen vacancies. The elucidation of this mechanism is one of the focuses of our research together with the optimization of the final properties. Persistent luminiscence materials have a wide range of applications in several fields. From classical applications (signaling, computer monitors, ceramic tiles, fluorescent toys, fluorescent lamps or paints) to new technologies such as plasma screens, electro-luminescent devices, LEDs or even in biomedicine.


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