An optical device includes an LED chip, a light absorber and/or visible-light luminescent material, and a near-infrared luminescent material, wherein a luminous power of light emitted by the near-infrared luminescent material and the light absorber and/or visible-light luminescent material in a band of 650-1000 nm under the excitation of the LED chip is A, and a sum of a luminous power of light emitted by the near-infrared and visible-light luminescent materials in a band of 350-650 nm under the excitation of the LED chip and a luminous power of residual light emitted by the LED chip in the band of 350-650 nm after the LED chip excites the near-infrared and visible-light luminescent materials is B, with B/A*100% being 0.1%-10%. According to the implementation where the optical device employs the LED chip to combine the near-infrared luminescent material and the light absorber and/or visible-light luminescent material simultaneously.

A phosphor includes, as a main component, a compound represented by a general formula (3-a)YO.sub.3/2.aCeO.sub.3/2.(5-b)AlO.sub.3/2.bGaO.sub.3/2.cKO.sub.1/2.dPO.sub.5/2, where a, b, c and d satisfy 0.12a0.18, 1.50b3.00, 0.01c0.08, and 0.01d0.08.

A device including an LED light source optically coupled to a green-emitting U.sup.6+-doped phosphor having a composition selected from the group consisting of U.sup.6+-doped phosphate-vanadate phosphors, U.sup.6+-doped halide phosphors, U.sup.6+-doped oxyhalide phosphors, U.sup.6+-doped silicate-germanate phosphors, U.sup.6+-doped alkali earth oxide phosphors, and combinations thereof, is presented. The U.sup.6+-doped phosphate-vanadate phosphors are selected from the group consisting of compositions of formulas (A1)-(A12). The U.sup.6+-doped halide phosphors are selected from the group consisting of compositions for formulas (B1)-(B3). The U.sup.6+-doped oxyhalide phosphors are selected from the group consisting of compositions of formulas (C1)-(C5). The U.sup.6+-doped silicate-germanate phosphors are selected from the group consisting of compositions of formulas (D1)-(D11). The U.sup.6+-doped alkali earth oxide phosphors are selected from the group consisting of formulas (E1)-(E11).

The present invention provides for a composition comprising an inorganic scintillator comprising an alkali metal hafnate, optionally cerium-doped, having the formula A.sub.2HfO.sub.3:Ce; wherein A is an alkali metal having a valence of 1, such as Li or Na; and the molar percent of cerium is 0% to 100%. The alkali metal hafnate are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

Ligand-capped inorganic particles, films composed of the ligand-capped inorganic particles, and methods of patterning the films are provided. Also provided are electronic, photonic, and optoelectronic devices that incorporate the films. The ligands that are bound to the inorganic particles are composed of a cation/anion pair. The anion of the pair is bound to the surface of the particle and at least one of the anion and the cation is photosensitive.