The structural and luminescent properties of trivalent europium-doped titanium dioxide films
synthesized by the ultrasonic spray pyrolysis technique at several substrate temperatures are
reported. These films are nanocrystalline and present a mixture of tetragonal (anatase and
rutile) crystal structures of the titania as determined by x-ray diffraction. The rutile crystal
structure became predominant as the substrate temperature during deposition was increased.
Under UV and electron beam excitation, these coatings showed strong luminescence due to f–f
transitions and the dominant transition was the hypersensitive 5D0 →7F2 red emission of Eu3+.
The photo- and cathodoluminescence characteristics of these films were studied as a function
of growth parameters such as substrate temperature and europium concentration. Excitation
with a wavelength of 396 nm resulted in photoluminescent emission peaks located at 557, 580,
592, 615, 652 and 703 nm, associated with the electronic transitions of the Eu3+ ion. The
photoluminescence (PL) intensity as a whole is observed to decrease as the deposition
temperature is increased. Also, with increasing doping concentration, a quenching of the PL is
observed. The chemical composition and surface morphology characteristics of the films are
also reported
