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In this paper, studies of the influence of luminescence additives on the optical and luminescence properties of polyurethane based organic polymers are presented. Absorption and transmittance spectra reveal a decrease of transmittance with increasing filler concentration. In the X-ray excited luminescence spectra of nanocomposite samples with an inorganic filler, no bands, related to self-trapped exciton (STE) or core-valence luminescence (CVL) luminescence of barium fluoride are observed. This is due to the overlap of the organic phosphor absorption band and barium fluoride emission band. Measurements of decay time constant also reveal no long component of STE luminescence. This may be due to non-radiative energy exchange between barium fluoride and PPO. [ABSTRACT FROM AUTHOR]

In this paper, studies of the effect of morphology and particle size of BaF2 nanopowders obtained by laser ablation method and by pulsed electron beam evaporation method on luminescent properties are presented. SEM-images of the morphology of all samples are presented. In the X-ray excited luminescence spectra of nanopowders, a redistribution of the relative intensity is observed between the self-trapped exciton and core-valence bands. This may be due to a smaller influence of particle size on the mechanism of formation of the cross-luminescence band. The change in the shape of the self-trapped exciton spectrum is also observed for nanosized samples. This effect can be associated with the possibility of the formation of certain STE configurations inside a nanoscale crystal due to the different relative position of the F and H centers parts with respect to each other. [ABSTRACT FROM AUTHOR]