Luminescence performance of europium-doped yttrium oxide thin films.

Europium-doped yttrium oxide thin films have been deposited by a spray pyrolysis method. The crystallite sizes are calculated to be ~50 nm using Scherrer׳s formula. Fourier transformed infrared spectroscopy (FTIR) reveals broad absorption with peak at 875 cm −1 . Surface morphology and elemental composition of the thin films are studied by a field-emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray spectroscopy (EDS). The energy gap ( E g ) of the thin film sample is found to be ~5.37 eV. The film exhibits photoluminescence (PL) emission over 525–550 nm, 585–601 nm, 612 nm and 620–632 nm under the excitation of 240 nm. Gamma (γ)-irradiated films exhibit two well-resolved thermoluminescent (TL) glows with peaks at 460 and 570 K. The TL glow curves are analyzed by a glow curve shape method. The activation energy and the frequency factor are found to be, respectively, ~0.6 eV, ~3×10 6 s −1 for 460 K and ~0.53 eV, ~46.72×10 3 s −1 for 570 K. [ABSTRACT FROM AUTHOR]