Preparation and photoluminescence properties of europium ions doped TiO2 nanocrystals.

In this paper, pure and Eu3+ doped TiO2 nanocrystals (NCs) have been fabricated successfully by a two steps of sol-gel and hydrothermal methods. The microstructures, morphologies and photoluminescent properties of Eu(3+)-TiO2 were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and photoluminescence spectroscopy (PL). XRD and PL results show that the existent of rare earth can inhibit the transformation of TiO2 NCs from anatase to rutile phase and can improve the luminescence intensity of the prepared samples. The room-temperature PL emission of the as-grown samples is dominated by the 5D(0)-7F(j) transitions of Eu3+ ions. But the luminescence intensity drops dramatically when the annealing temperature reaches a relatively high degree because of the formation of the rutile phase of TiO2 NCs hosts.