Single-phase cool white-light emitting BaNb₂O₆:Dy³⁺ phosphors have been synthesized and their structural, luminescence and colorimetric properties have been investigated in detail.

We report a simple method for the synthesis of ultra-fine Eu(3+)-doped yttria (Y(2)O(3)) nanophosphors with an average diameter of approximately 5 nm for development of a transparent colloid that could be used as a luminescent security ink. This has been achieved by suitably substituting Eu(3+) ions at the favorable C(2) symmetry sites of Y(3+) ions and quantum mechanically confining the growth of the nanophosphor using a novel acid-catalyzed sol-gel technique. This is one of the few reports that depict the development of a transparent aqueous-stable Y(2)O(3):Eu(3+) colloidal solution for strategic applications related to security codes. High resolution transmission electron microscopy images showed excellent lattice fringes that in turn support the presence of better crystal quality and enhanced photoluminescence (PL) emission from the Y(1.9)O(3)Eu(0.1)(3+) nanophosphor system. Time resolved emission spectroscopy measurement indicated a PL decay time in the range of a few milliseconds, suitable for making luminescent security ink and other advanced applications in optoelectronic devices and bio-labeling.

Results pertaining to the development of highly dispersible stand-alone particles of ${\mathrm{Ce}}^{3+}$ -doped ${\mathrm{Y}}_3{\mathrm{Al}}_5{\mathrm{O}}_{12}$ nanophosphor and their luminescence are presented. The yellow light-emitting nanophosphor was produced as a result of a single-step auto-combustion process, which requires no auxiliary annealing treatments prior to any practical application. The structure, photoluminescence, and chromaticity of the powder nanophosphor samples with the compositions ${\mathrm{Y}}_{(3-x)}{\mathrm{Al}}_5{\mathrm{O}}_{12}:x{\mathrm{Ce}}^{3+}$ $(x=0.01–1)$ are featured in the letter. The nanophosphor absorbs light efficiently in the visible region of $400–500\mathrm{nm}$ , and shows single broadband emission peaking at $\sim 560\mathrm{nm}$ . The luminescence yield is almost analogous to the samples made from other conventional methods. Hence, it could be an apt candidate for generating white light when coupled to a blue light-emitting diode $({\lambda }_{\mathrm{em}}=450\mathrm{nm})$ .