Luminescent properties of silica and zirconia xerogels doped with europium(III) salts and europium(III) cryptate incorporating 3,3′-biisoquinoline-2,2′-dioxide

Eu+3 cryptate with 3,3′-biisoquinoline-2,2′-dioxide unit was incorporated into glass films consisting of zirconia dioxide and into hybrid ormosil films. The absorption and the emission intensities of the europium complex were compared to the intensity of the non-complexed europium ion in the films. The transition probabilities of the complex are increased as a result of the mixing of the europium orbitals with the ligand orbitals. The emission is additionally increased as the non-radiative relaxation is diminished by the cage effect.