Photoluminescence properties of TiO2: Eu3 + thin films deposited on different substrates

Strong photoluminescence of Eu3 + due to intra 4f transitions are obtained from amorphous xerogel TiO2: Eu3 + films prepared by sol–gel method and treated at a low temperature of 100 °C. The films are deposited on four different substrates: Si, Al, AAO (anodic alumina oxide) and porous silicon. We find that the luminescence intensity on AAO substrate increased 4 times comparing with that of Si or Al, and luminescence intensity decreases obviously on porous silicon substrate. Energy transfer mechanism from TiO2 host to Eu3 + is deduced through analysis of photoluminescence and photoluminescence excitation spectrum. Concentration quenching of Eu3 + does not appear even at high atomic concentration of 7.69%.