Synthesis In Situ, Characterization, and Photostability of Europium β-Diketone Chelates in Organically Modified Silicates (ORMOSILs)

Abstract

Europium β-diketonates have desirable optical properties, and transparent inorganic materials that have been doped with these chelates seem to be promising for potential applications in luminescence-display devices, integrated optical device sources, and new visible lasers. However, these chelates may be decomposed or not dissolved in sol—gel precursor solutions and, thus, cannot be doped in gel glasses that have been prepared via traditional sol—gel processing. An in situ synthesis technique has been used for the first time to synthesize five binary and ternary coordination compounds of europium β-diketonates in transparent organically modified silicates (ORMOSILs) during heat treatment or during the process of sol-to-monolithic ORMOSIL conversion. ORMOSILs that have been doped with in situ europium β-diketonates exhibit rather-high fluorescence intensity and good monochromati-city. These materials result in enhanced red-light emission under ultraviolet excitation. The chelates that have been synthesized in situ in the ORMOSILs reveal better photostability, in comparison to that of the pure chelates that have been dissolved in ethanol solutions.