Up-conversion luminescence of hafnium, erbium, ytterbium and lithium co-doped yttrium oxide

Abstract

UP-conversion luminescence of hafnium, erbium, ytterbium and lithium multiple doped yttrium oxide powders are presented. The measured luminescent spectra were obtained using two different lasers with wavelengths of 980 and 1534 nm; emission peaks were observed in the ranges of 530–580 nm (green emission), 630–680 nm (red emission), 960–1100 nm (infrared emission) and 1510 to 1560 (infrared emission) corresponding to the different intra electronic energy levels transitions of the Er3+ and Yb3+ ions. These emission peaks manifest the interactions between these ions that propitiate the phenomenon of up-conversion. The incorporation of lithium in the samples allowed an increase in the luminescent emission of up to 88% for the red emission and up to 12% for the emission in the IR range with respect to the samples that were not doped with lithium. The powders, object of this study, were synthesized by means of the solvent evaporation technique using nitrates and chlorides as precursors. The analysis of XRD showed a cubic crystalline structure of yttrium oxide with the spatial group: Ia-3 (206). The obtained SEM images showed a granular morphology only for samples doped with lithium with dimensions less than a micron. The chemical composition was obtained by measurements of EDS and FT-IR and finally the decay times of the different luminescent emissions are also reported.