Highly Photoluminescent Silica Layers Doped with Efficient Eu(III) and Tb(III) Antenna Complexes

Eu(III) and Tb(III) antenna complexes employing different units-phenanthroline and acetophenone derivatives-for light absorption and sensitization of the lanthanide (Ln) emitting states, have been synthesized and successively anchored in silica layers by the sol-gel technique. The luminescence properties of the complexes, preliminarily studied in H2O and D2O solutions, were improved in the oxide host matrix, showing the effectiveness of the employed synthesis route for the preparation of efficient molecular-based light-emitting materials. All the prepared films were highly transparent and homogeneous and displayed a bright red (Eu3+) or green (Tb3+) luminescence notwithstanding the low luminophore content (Ln/Si = 1/400 or 1/100 molar ratios) and limited film thickness (<= 140 nm). It is worth highlighting that the silica layers containing the Tb3+ complex bearing in acetophenone derivative as an antenna are characterized by photoluminescence quantum yields as high as 45%.