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 (Eg) 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, ~3×106 s−1 for 460 K and ~0.53 eV, ~46.72×103 s−1 for 570 K.