Photoluminescent films of microporous titanosilicate ETS-10 doped with europium(III)

Eu3+-ETS-10 powders and films supported on dense α-alumina and stainless steel substrates have been prepared via seeded hydrothermal synthesis, followed by conventional ion-exchange, and characterised by X-ray diffraction and scanning electron microscopy. ETS-10 films and powders exhibit different photoluminescence characteristics, which have been studied in detail. In particular, for powdered samples direct Eu3+ excitation is comparable to excitation sensitized via lattice energy levels, whereas this latter process largely dominates in films. The emission spectra (intra-4f6 transitions) and the (corresponding 5D0) decay curves, reveal the presence of two distinct Eu3+ local environment in Eu3+-doped ETS-10 powders (Ti/Eu = 10), whereas in films only a single Eu3+ site seems to be present, even at relatively high Eu3+ contents (Ti/Eu = 6, 5). Possible reasons for this disparate behaviour have been discussed.