Effect of low-density polyethylene on the luminescent properties of thulium-doped yttrium oxide obtained by the polyol technique

In the present work polyethylene is used as a support of yttrium oxide particles doped with thulium atoms and its effect on the luminescent properties is studied. Thulium-doped yttrium oxide was prepared through the polyol method, different values of thulium are explored: 0, 0.5, 1, 1.5, 2.5 and 3.5 at%, as well as different calcinating temperatures: 400, 600, 800 and 1000 °C, are explored in order to determine the synthesis conditions needed for the maximum emission intensity, whose values were 1.5 at% of thulium and 1000 °C. The synthesized powder is dispersed in low-density polyethylene and dispersed as a thin film on glass substrates. The luminescent excitation and emission spectra showed important changes attributed to the influence of the -CH₂- chain vibration; in addition, the presence of the polymer had an important influence on the emission decay time: while the powder showed a single emission process with a time of 9.293 μs, the film showed a two decay process with 1.156 μs and 4.086 μs, each.