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 calcd. to be ∼50 nm using Scherrer's formula. Fourier transformed IR spectroscopy (FTIR) reveals broad absorption with peak at 875 cm-​1. Surface morphol. and elemental compn. 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, resp., ∼0.6 eV, ∼3×106 s-​1 for 460 K and ∼0.53 eV, ∼46.72×103 s-​1 for 570 K