Luminescence properties of ORMOSIL films doped with terbium complexes

Luminescence properties of sol-gel SiO₂-TiO₂ ORMOSIL films doped with various terbium complexes were studied. 3-(Trimethoxysilyl) propyl methacrylate and tetraisopropyl-orthotitanate complexed with methacrylic acid were used as sol-gel precursors for film deposition. In situ rare earth complexation was performed through the direct incorporation of TbCl₃ and 1,10-phenanthrolin (Phen), phthalic acid (Phta), or 2,2′-bipyridyl (Bipy) ligand in the sol-gel precursor solution. ORMOSIL coatings were deposited using the aerosol-gel process, which is an original deposition method based on the sol-gel polymerization of a liquid film produced from an ultrasonically sprayed aerosol. ORMOSIL films containing terbium complexes exhibited a strong green emission, which was intensified through post-treatment temperature optimization. The highest photoluminescence intensities were measured on films doped with Tb(Phen)³⁺ complex and heat treated at 150 °C, while films doped with Tb(Bipy)³⁺ complex and heat-treated at the same temperature exhibited the longest lifetimes.