Luminescence, energy transfer, and upconversion mechanisms of Y2O3 nanomaterials doped with Eu3+, Tb3+, Tm3+, Er3+, and Yb3+ ions

Luminescence, energy transfer, and upconversion mechanisms of nanophosphors (Y2O3 : Eu3+, Tb3+, Y2O3 : Tm3+, Y2O3 : Er3+, Yb3+) both in particle and colloidal forms were studied. The structure, phase, and morphology of the nanopowders and nanocolloidal media were determined by high-resolution TEM and X-ray diffraction. It was shown that the obtained nanoparticles have a round-spherical shape with average size in the range of 4 to 20 nm. Energy transfer was observed for Y2O3 : Eu3+, Tb3+ colloidal and powders, upconversion transitions were observed for both Y2O3 : Er3+ and Y2O3 : Er3+, Yb3+ nanophosphors. The dependence of photoluminescence (PL) spectra and decay times on doping concentration has been investigated. The infrared to visible conversion of emission in Y2O3 : Er3+, Yb3+ system was analyzed and discussed aiming to be applied in the photonic technology. Copyright (C) 2007 TranKim Anh et al.